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What is an SA400 Form?

Updated: Jan 4

The HMRC SA400 form is a document that you fill out and submit to HM Revenue & Customs (HMRC) in the UK. It's used to report any income that you received during the tax year from sources other than employment, such as rental income or income from investments.


In other words, if you made money in ways other than just through your job, you need to report it on this form. The SA400 form is part of the self-assessment tax return process and helps HMRC to calculate the amount of tax you owe on your total income. The HMRC SA400 form is a document that you fill out and submit to HM Revenue & Customs (HMRC) in the UK. It's used to report any income that you received during the tax year from sources other than employment, such as rental income or income from investments.


The HMRC SA400 form is an essential document in the UK's tax system, particularly for partnerships. As of 2024, its role in ensuring tax compliance and facilitating the self-assessment process for partnerships remains crucial. This article delves into the specifics of the SA400 form, its purpose, how to complete it, and its significance in the UK's tax landscape in 2024.


Understanding the HMRC SA400 Form

The SA400 form is used by partnerships in the UK to register for Self Assessment with HM Revenue & Customs (HMRC). It's a critical step in the tax compliance process for partnerships. The form is designed to capture essential information about the partnership, such as the name and address of the partnership, business phone number, type of business, date of partnership commencement, partnership type, and partnership accounting date​​​.


So if you made money in ways other than just through your job, you need to report it on this form. The SA400 form is part of the self-assessment tax return process and helps HMRC to calculate the amount of tax you owe on your total income. Use the SA400 form to register a business partnership for Self-Assessment, or register for it online. Registration of your partnership in HMRC is essential, to enable the partner named (chosen from the partners) to submit Self-Assessment tax returns. This ensures that the business partnership is able to pay any tax they owe.


What is an SA400 Form?


Purpose of the SA400 Form

The primary purpose of the SA400 form is to report income received during the tax year from sources other than employment. This includes rental income, income from investments, and other forms of non-employment income. By registering a partnership for Self Assessment, HMRC is informed about the existence of the partnership and its tax obligations. This ensures that HMRC can expect accurate and timely tax returns from the partnership​​.


Importance of the SA400 Form in 2024

In 2024, the importance of the SA400 form in the UK lies in its role in maintaining the integrity of the tax system, especially for partnerships. It helps HMRC in:

  1. Identifying and keeping track of partnerships and their tax responsibilities.

  2. Ensuring that partnerships are correctly registered for Self Assessment and are compliant with their tax reporting obligations.

  3. Facilitating the accurate calculation of taxes due from partnerships based on their reported income and allowable expenses.


Registration Deadlines and Compliance

For partnerships that started in a specific tax year, the SA400 form must be submitted by a certain deadline to ensure compliance with HMRC requirements. For instance, a partnership that began in February 2023 would need to register with HMRC for the tax year 2023/24 (which runs from 6th April 2023 to 5th April 2024) before the deadline of 5th October 2023​​. Adhering to these deadlines is crucial to avoid penalties and ensure that the partnership remains in good standing with HMRC.


The HMRC SA400 form is a vital tool in the UK tax system for partnerships. Its role in facilitating tax compliance and ensuring accurate tax reporting cannot be understated. As of 2024, understanding and correctly using the SA400 form remains crucial for partnerships in the UK to meet their tax obligations and avoid potential issues with HMRC. The form not only serves to register a partnership for Self Assessment but also helps in the accurate assessment of taxes due, reinforcing the importance of tax compliance and integrity in the UK's financial system.


Completing SA400

In order to register your partnership, you must name the partner you want to nominate. Then, the partner is required to complete SA400. SA400 form can either be filled out and submitted online (using Govt. Gateway) or filled online and printed and mailed the form to HMRC or SA400 can be filled in PDF and mailed to HMRC. The SA400 form has two pages, and you'll require the following information in order to fill out the form:


● The name of the company.

● Address of the business.

● Contact details of the business.

● Business type.

● The date of the start of the partnership.

● Type of Partnership.

● Partnership accounting date.

● Address and name of the chosen partner.


How are Different Sections of HMRC SA400 Form Filled?

The HMRC SA400 form in the UK is divided into several sections, each of which asks for different types of information. Here's a breakdown of how to fill out each section:


Your Personal Details: In this section, you'll need to provide your name, address, National Insurance number, and other personal information. Make sure to double-check your entries to ensure they're accurate.

Income From Property: If you earned income from renting out property or other sources, you'll need to report it in this section. You'll need to provide details about each property you rented out, as well as any expenses related to the property.

Capital Gains: If you sold any assets, such as stocks or property, you'll need to report any gains or losses in this section. You'll need to provide details about the asset, the sale price, and any associated expenses.

Other Income: This section is for reporting any other income you received during the tax year that isn't covered in the previous sections. This might include income from investments, self-employment, or other sources.

Tax Deducted at Source: If you had any taxes deducted from your income at the source, such as from a pension or employment, you'll need to report it in this section. You'll need to provide details about the source of the income and the amount of tax deducted.

Tax Relief: This section is for reporting any tax relief you may be eligible for, such as for charitable donations or pension contributions.

Declaration: Finally, you'll need to sign and date the declaration at the end of the form to confirm that the information you've provided is accurate and complete.



How to Complete Different Sections of the HMRC SA400 Form - A Step by Step Guide

Completing the HMRC SA400 form accurately is crucial for partnerships in the UK to register for Self Assessment. This step-by-step guide will walk you through the different sections of the form, based on the 2023 version of the SA400 form.


1. About the Partnership

This section requires basic information about your partnership.

  • Name of Partnership (Section 1): Enter the official name of your partnership as registered.

  • Address and Phone Number (Sections 2 and 3): Provide the partnership's official address and a contact phone number.

  • Trading Name (Section 4): If different from the official name, enter the trading name of the partnership.

  • Trading Address (Section 5): If different from the official address, enter the trading address.

  • Nature of Business (Section 6): Describe the type of business your partnership is engaged in, such as 'plumbers' or 'investment business'.

  • Business Commencement Date (Section 7): Enter the date when the business started operations.

  • Partnership Type (Section 8): Specify the type of partnership – Partnership, LLP, or LP.

  • Company Registration Number (Section 9): For LLPs or LPs, provide the Company Registration Number (CRN).

  • Accounting Date (Section 10): Indicate the partnership’s accounting date.


2. About the Partnership Continued

This part focuses on the nominated partner and their details.

  • Name of Nominated Partner (Section 11): Enter the name of the partner nominated to handle and submit partnership returns.

  • Correspondence Address (Section 12): Provide the address for correspondence related to the nominated partner.

  • Unique Taxpayer Reference (UTR) (Section 13): If the nominated partner is already registered for Self Assessment, enter their UTR.


3. Declaration

The declaration is a critical part of the form where the nominated partner attests to the accuracy of the information provided.

  • Name of Nominated Partner (Section 14): Re-enter the name of the nominated partner.

  • Declaration and Signature (Sections 15 and 16): The nominated partner must declare that the information is complete and correct, and then sign and date the form.


4. What to Do Next

This section provides instructions on what to do after completing the form.

  • Sending the Form (Section 17): You must send the completed SA400 form to HMRC, along with any completed SA401, SA402, and 64-8 forms. The address for submission is provided in the form.

  • Number of Forms Enclosed (Section 18): Indicate how many additional forms are enclosed with the SA400.

Tips for Completing the Form:

  • Accuracy is Key: Ensure that all information provided is accurate and up-to-date.

  • Supporting Documents: Make sure to include any required supporting documents.

  • Deadlines: Submit the form before the deadline to avoid penalties.


Completing the HMRC SA400 form is a straightforward process, but it requires attention to detail. By following this guide and ensuring that each section is accurately filled out, partnerships can smoothly register for Self Assessment and remain compliant with UK tax laws. Remember, the nominated partner plays a crucial role in this process, and their signature on the form is a declaration of the accuracy of the information provided.



How is HMRC SA400 Form Submitted?

Filling out and submitting the HMRC SA400 form in the UK is a relatively straightforward process. Here are the basic steps you'll need to follow:


  1. Gather Your Information: Before you start filling out the form, you'll need to gather all the relevant information about your income and expenses. This may include bank statements, receipts, and other financial documents.

  2. Complete The Form: You can download the SA400 form from the HMRC website or request a paper copy by mail. The form will ask you to provide details about your income and expenses, as well as any tax deductions or allowances you may be eligible for. Make sure to fill out the form accurately and legibly.

  3. Check Your Work: Once you've completed the form, double-check your entries to make sure you haven't made any mistakes or left anything out. It's a good idea to have someone else review the form as well, just to be safe.

  4. Submit The Form: You can submit the form to HMRC either online or by mail. If you're filing online, you'll need to register for an HMRC online account and follow the prompts to upload your completed form. If you're filing by mail, you'll need to send the form to the address provided on the form.

  5. Pay Any Taxes Owed: If your form indicates that you owe taxes, you'll need to pay them by the deadline specified by HMRC. You can pay online, by phone, or by mail.


Overall, the process of filling out and submitting the HMRC SA400 form is fairly simple, but it's important to take the time to do it accurately to avoid any issues or penalties. If you have any questions or need help, don't hesitate to contact HMRC or a tax professional.



What is an SA401 Form?

The HMRC SA401 form in the UK is a supplementary form that you can use to provide additional information about your income on your self-assessment tax return. This form is used in situations where the information requested on the main SA400 form isn't sufficient to accurately report your income.


For example, you might use the SA401 form if you received income from a foreign country that wasn't reported on the SA400 form, or if you had income from a partnership or trust. The SA401 form allows you to provide more detailed information about these types of income so that HMRC can accurately calculate the amount of tax you owe.


Use the SA401 to check in as an associate for Self-Assessment and Class 2 National Insurance contributions. It contains questions that help HMRC decide your tax returns and Class 2 NICs necessities. The partners must sign up one by one for the form SA400. Registering a partnership for Self-Assessment. Partners who aren’t individuals, for example, agencies, Limited Liability Partnerships (LLPs), and trusts must entirely form SA402. Each associate has to sign an entirely separate form SA401 or SA402, as appropriate. This applies even if the partners have already sent in tax returns and are registered for Self-Assessment in their very own right.


To sign up you can:


1. Use the Web Carrier

2. Fill in Form On-Display, Print, and Post to HMRC


To use the web carrier, you want a Government Gateway user ID and password. If you do not have a user ID you may create one when you use the provider. You need to fill in the form fully before you print it as you cannot send an in-part finished form. So you ought to acquire all your statistics collectively before you start to fill it in. If you've got trouble beginning the web-based form you may use the PDF model. You’ll have to print this and fill it in by way of hand before posting it to HMRC.


How is HMRC SA401 Form Filled?


The HMRC SA401 form in the UK is a supplementary form used to provide additional information about your income. Here's a breakdown of how to fill out each section of the SA401 form:



  1. Personal Details: In this section, you'll need to provide your name, address, and National Insurance number.

  2. Foreign Income: If you received income from a foreign country, you'll need to report it in this section. You'll need to provide details about the income, including the type of income, the source of the income, and the amount.

  3. Partnership Income: If you received income from a partnership, you'll need to report it in this section. You'll need to provide details about the partnership, including the name and address of the partnership, the type of partnership, and your share of the income.

  4. Trust Income: If you received income from a trust, you'll need to report it in this section. You'll need to provide details about the trust, including the name and address of the trust, the type of trust, and your share of the income.

  5. UK Dividends: If you received dividends from UK companies, you'll need to report them in this section. You'll need to provide details about the dividends, including the name of the company, the amount of the dividends, and any tax credits associated with the dividends.

  6. Non-UK Dividends: If you received dividends from non-UK companies, you'll need to report them in this section. You'll need to provide details about the dividends, including the name of the company, the amount of the dividends, and any tax credits associated with the dividends.

  7. Other Income: If you received any other income that wasn't reported on the main SA400 form, you'll need to report it in this section. You'll need to provide details about the income, including the type of income, the source of the income, and the amount.


It's important to fill out each section of the SA401 form accurately and completely to ensure that your tax return is complete and accurate. If you're not sure how to fill out a particular section, you can seek help from HMRC or a tax professional.


What is an SA402 Form?

The HMRC SA402 form in the UK is a supplementary form that you can use to claim a tax exemption or tax relief on your self-assessment tax return. This form is used in situations where you're eligible for a specific tax exemption or relief that isn't covered by the main SA400 form.


For example, you might use the SA402 form to claim a tax exemption for the income you received from certain types of investments or to claim relief for pension contributions you made during the tax year. The SA402 form allows you to provide more detailed information about these types of exemptions and reliefs so that HMRC can accurately calculate the amount of tax you owe.


Use the SA402 to register an accomplice (partner) who isn't a person (like a man or woman) for Self-Assessment. The liable partner, for instance, a trustee or an enterprise secretary, should sign this form. Each business partnership should nominate a partner who takes responsibility for completing and submitting statistics to HMRC on time. It’s their obligation to apply through online form SA402 or to register their partnership in any other/second partnership.


You could:


1. Use the Online Form

2. Fill in Form On-Display Screen, Print, and Post to HMRC


To use the online service, you need a Government Gateway user ID and password. If you do not have a user ID you could create one online through the online portal of HMRC. Fill in the form before you print it as you can't save a partly finished form so you must accumulate all your facts together before you begin to fill it in.


If you have trouble using the web-based form you may use the PDF version, you’ll need to print this and fill it in by hand earlier than posting it to HMRC.



How is HMRC SA402 Form Filled?

The HMRC SA402 form in the UK is a supplementary form used to claim a tax exemption or relief on your self-assessment tax return. Here's a breakdown of how to fill out each section of the SA402 form:


Personal Details: In this section, you'll need to provide your name, address, and National Insurance number.

Type of Exemption or Relief: You'll need to indicate the type of exemption or relief you're claiming on the form. This might include, for example, relief for pension contributions or an exemption for certain types of investment income.

Amount Claimed: You'll need to provide the amount of the exemption or relief you're claiming on the form. Make sure to double-check your entries to ensure they're accurate.

Basis of the Claim: In this section, you'll need to provide information about the basis of your claim for the exemption or relief. This might include, for example, providing details about your pension contributions or investment income.

Declaration: Finally, you'll need to sign and date the declaration at the end of the form to confirm that the information you've provided is accurate and complete.


Are There Partners who are Registered as Separate from the Partnership?

This partnership has been registered to Self-Assessment in its own right. Every partner in the partnership will be required to sign up for tax payments. When the partnership partner is an independent and is a sole trader, they must register in the sole trader category in self-assessment for the purpose of paying the tax on their income in addition to Class 2 National insurance contributions. Partners could also be a partnership or a limited business.


It is important to ensure that the partnership must be registered in order to pay any taxes that are required. Every partner should be registered to pay taxes on the profits they earn from the partnership.


What are the Various types of Partnerships?

There are three kinds of business partnerships. It is important to inform HMRC about the kind of partnership your company is setting up.


Ordinary Partnership

A normal partnership is considered to be the most commonly used and straightforward way of allowing two to three persons to join a business. The partnership has no formal entity that is shared by the partners themselves which means that the partnership has to dissolve if any partner leaves or dies or becomes bankrupt. The business may continue, however not in the manner of the original partnership.


Limited Partnership

A limited partnership may comprise a combination of ordinary and limited partners. The liability of a limited partner is restricted to the amount that is invested in the company and personal guarantees in connection with any loan or credit facility. Limited partnerships must be registered with the company house, which then informs HMRC regarding the partnership. HMRC automatically sets up the partnership records, so it is not necessary to register an additional filing with HMRC. Normally, accounts and an annual return are not required to be filed with the company's house.


Limited Liability Partnership

Limited liability partnerships, also known as LLPs, as they are commonly referred to, are classed as a corporation with members who have limited liability. There must be at minimum two members designated in the restricted liability partnership. LLPs have to sign up a partnership with a company house, which will notify HMRC and inform HMRC of the association. HMRC will then create a record for the LLP so an additional filing with HMRC is not necessary. The LLP has to file annually a tax return and keep accounts with the company house.


Will My Partnership Be Given the Benefit of Its Individual UTR Number?

Yes, the partnership will be issued its own UTR number after it has been registered. Each partner will receive their individual UTR number at the time of registration to register, so be sure not to duplicate them!




Why is it a Good Idea to Get Professional Help to Form a Partnership Business?

If you're considering forming a partnership business in the UK, you might be wondering whether it's necessary to seek professional help. While it's certainly possible to form a partnership on your own, there are many good reasons why it's a good idea to get professional help.


Here are some of the key reasons why you might want to consider seeking professional help to form a partnership business in the UK:


Legal Considerations

One of the most important reasons to seek professional help is to ensure that you comply with all the legal requirements for forming a partnership. This includes registering the partnership with HM Revenue & Customs (HMRC) for tax purposes and making sure that your partnership agreement is legally sound. A lawyer or other legal professional can help you navigate the legal requirements and ensure that your partnership is set up correctly.


Tax Considerations

Another important consideration when forming a partnership is the tax implications. Partnerships are not taxed as separate entities, which means that each partner is responsible for paying tax on their share of the partnership profits. A tax professional can help you understand the tax implications of your partnership and make sure that you're paying the correct amount of tax.


Partnership Agreement

While it's possible to form a partnership without a written agreement, it's highly recommended to have one in place. A partnership agreement is a legal document that outlines the terms and conditions of the partnership, including how profits will be shared, how decisions will be made, and how disputes will be resolved. A lawyer can help you draft a partnership agreement that's tailored to your specific needs and ensures that your interests are protected.


Financial Considerations

When forming a partnership, it's important to have a solid financial plan in place. A financial professional can help you create a budget, forecast your revenue and expenses, and develop a plan for managing cash flow. This can help you avoid financial pitfalls and ensure that your partnership is financially stable.


Business Planning

Finally, forming a partnership requires careful planning and preparation. A business consultant or other professional can help you develop a business plan, identify your target market, and develop marketing and sales strategies. This can help you set your partnership up for success from the outset and increase your chances of long-term success.


While it's certainly possible to form a partnership business on your own, seeking professional help can help you avoid common pitfalls and ensure that your partnership is set up for success. Whether you need legal, tax, financial, or business planning assistance, there are many professionals available who can help you navigate the process and set your partnership up for success.


Help with HMRC SA400 Form

Filling out the HMRC SA400 form, a key document for registering a partnership for Self Assessment in the UK, can be a complex process. Given its importance in ensuring tax compliance, many partnerships choose to seek professional assistance. This article explores the reasons why getting professional help with the SA400 form is beneficial.


Understanding the Complexities

The SA400 form involves various sections that require detailed information about the partnership. Professionals, such as accountants or tax advisors, are well-versed in these complexities and can ensure that all necessary details are accurately provided. Their expertise can be particularly valuable in interpreting the specific requirements of each section, ensuring that the partnership's unique circumstances are correctly represented on the form.


Avoiding Errors and Omissions

Mistakes or omissions in the SA400 form can lead to delays or issues with HMRC. Professionals are meticulous in their approach, significantly reducing the risk of errors. They can cross-verify the information, ensuring that nothing is missed and that all entries are error-free. This meticulousness can be crucial, especially in complex partnership structures or when dealing with intricate financial details.


Saving Time and Effort

Completing the SA400 form can be time-consuming, especially for those unfamiliar with tax forms. By engaging a professional, partnerships can save considerable time and effort. These experts can handle the entire process, from gathering information to filling out and submitting the form, allowing the partners to focus on their business operations.


Staying Updated with Latest Tax Laws

Tax laws and regulations can change frequently. Professionals stay abreast of the latest updates, ensuring that the information provided on the SA400 form is in line with current regulations. This is particularly important as tax laws can have significant implications on how partnerships report their income and calculate their tax liabilities.


Maximizing Tax Efficiency

An expert can provide advice on how to structure the partnership's affairs in the most tax-efficient manner. This can include guidance on allowable expenses, tax deductions, and reliefs that the partnership may be entitled to. By optimizing the partnership's tax position, a professional can help in legally minimizing the tax burden.


Dealing with Complications

Some partnerships may have complex structures or financial arrangements that make the registration process more challenging. Professionals can navigate these complexities with ease, ensuring that the form is completed accurately and in compliance with HMRC requirements. This is particularly important for partnerships with intricate business operations or those involved in multiple business ventures.


Ensuring Compliance

Tax compliance is a crucial aspect of running a partnership.

Professionals can ensure that the partnership adheres to all HMRC requirements, reducing the risk of penalties or legal issues. This compliance extends beyond just filling out the form; it also involves understanding the ongoing obligations and ensuring that the partnership remains compliant in the future.


Peace of Mind

Knowing that an expert is handling the registration process can provide peace of mind. Partners can be confident that their tax affairs are in capable hands, reducing stress and allowing them to focus on other aspects of their business.


Support in Case of Queries or Audits

In the event of any queries from HMRC or if the partnership is selected for an audit, having a professional who is familiar with the partnership's tax affairs can be invaluable. They can provide the necessary support and representation, ensuring that the partnership's interests are adequately protected.


Building Long-term Relationships

Engaging with a professional for the SA400 form can be the beginning of a long-term relationship. As the partnership grows and evolves, having a consistent tax advisor can be beneficial for strategic tax planning and ongoing compliance.


In summary, seeking professional help with the HMRC SA400 form can offer numerous benefits to partnerships. From ensuring accuracy and compliance to providing peace of mind, the expertise of a tax professional can be invaluable. It allows partnerships to navigate the complexities of tax registration and reporting with confidence, ensuring that they remain focused on their business goals while adhering to tax obligations.


Speak to one of our advisers to discuss our online accounting solutions for partnerships by dialing 07985689912.



Q1: Is the SA400 form mandatory for all types of partnerships in the UK?

A: Yes, all types of partnerships in the UK need to complete the SA400 form to register for Self Assessment with HMRC.


Q2: Can the SA400 form be submitted electronically?


A: Yes, the SA400 form can be filled out and submitted online using the Government Gateway, or it can be completed as a PDF and mailed to HMRC​.


Q3: What is the deadline for submitting the SA400 form?

A: The deadline for submitting the SA400 form depends on the tax year for which the partnership is registered. Generally, it needs to be submitted by a specific deadline to comply with HMRC requirements​.


Q4: What types of income need to be reported on the SA400 form?

A: Income from sources other than employment, such as rental income or income from investments, should be reported on the SA400 form​.


Q5: What is the purpose of the SA401 form?

A: The SA401 form is a supplementary form used to provide additional information about your income, especially in cases where the main SA400 form doesn't capture all necessary details​.


Q6: How is the SA402 form different from the SA400 form?

A: The SA402 form is another supplementary form used to claim tax exemptions or reliefs not covered by the SA400 form, such as for certain types of investments or pension contributions​.


Q7: What are the key types of partnerships recognized in the UK?

A: The UK recognizes three main types of partnerships: Ordinary Partnership, Limited Partnership, and Limited Liability Partnership (LLP)​.


Q8: Are Limited Partnerships and LLPs required to file the SA400 form?

A: Yes, all types of partnerships, including Limited Partnerships and LLPs, must file the SA400 form for tax purposes.


Q9: Does each partner in a partnership need to fill out a separate SA400 form?

A: No, only the nominated partner needs to complete and submit the SA400 form on behalf of the partnership.


Q10: Can a partnership use the SA400 form to register for VAT?

A: The SA400 form is specifically for Self Assessment registration. VAT registration is a separate process.


Q11: What information about the partnership is required on the SA400 form? A: Information required includes the partnership's name, address, type of business, date of commencement, and partnership accounting date​.


Q12: Is it necessary to provide personal details of the partners on the SA400 form? A: Personal details of the nominated partner, such as their name and address, are required on the form​.


Q13: What happens if the SA400 form is submitted after the deadline?

A: Late submission of the SA400 form can result in penalties and may affect the partnership's good standing with HMRC​.


Q14: Can the SA400 form be used to report foreign income?

A: Yes, if you have foreign income, it needs to be reported on the SA400 form or the supplementary SA401 form, depending on the details​.


Q15: What is the significance of the accounting date mentioned in the SA400 form? A: The accounting date is crucial for determining the tax year for which the partnership needs to report its income and expenses.


Q16: What are the implications of incorrectly filling out the SA400 form?

A: Incorrect information can lead to incorrect tax calculations and potential legal issues with HMRC.


Q17: Can changes be made to the SA400 form after submission?

A: If errors are discovered after submission, you should contact HMRC as soon as possible to rectify the information.


Q18: Is professional assistance recommended for completing the SA400 form?

A: Yes, seeking professional help can ensure compliance with legal and tax requirements and accuracy in filling out the form​.


Q19: How long does it take to process the SA400 form after submission?

A: The processing time can vary; however, you should receive confirmation from HMRC once the form is processed.


Q20: Are there any specific guidelines for partnerships formed mid-tax year? A: Partnerships formed mid-tax year still need to register using the SA400 form and comply with the specific deadlines for that tax year.


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