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What your accountant needs to file your tax return
Providing your accountant with everything they need to prepare your tax return ahead of the self-assessment tax return deadline will mean your tax return is processed smoothly. Our guide explains what your accountant will need to file your tax return so you can ensure they have what they need.
Last updated 19 May 2026 | First published 17 Dec 2019
By Helen Wood, CA 3 min read
Self-Assessment Tax Returns
Here is a simple breakdown of what records your accountant will need to produce your accounts and your self-assessment tax return. The tax return due to be filed by 31st January 2027 is the 2025/2026 tax return which covers the tax year from 6th April 2025 to 5th April 2026.
If you're self-employed and require your accounts to be prepared alongside your tax return, following basis period reform your accounting period may be different from your tax year if your accounting year-end isn't between 31st March and 5th April.
Basis period reform moves the taxation basis from "current year basis" to "tax year basis". Speak to your accountant if you need more information about your accounting period.
What self-assessment tax return records does my accountant need?
- Employment Income: If you have any employment income, you will need to provide your P60 or P45.
- P11d: If you receive any benefits-in-kind as part of your employment that have not been taxed through payroll.
- Dividends: Documentation for any dividends received during the year, either from your company or investments in other companies.
- Rental income: Your accountant will need to see details of your rental income and property management expenses.
- If you have a letting agent, provide your accountant with your monthly statements.
- If you have a mortgage, details of any mortgage interest paid throughout the year should be sent to your accountant.
- Details of any costs paid in relation to the rental property expenses.
- Private pension contributions: Confirm to your accountant any personal pension contributions made.
- Charitable donations: If you have made any gift aid donations, send details to your accountant.
- Bank interest received: Any interest received during the year (excluding ISAs).
- Other income or gains: Anything else you have received, that may be taxable, let you accountant know. This may be from your side hustle or a capital gain from selling a rental property, shares or other assets.
Organising your finances and getting this information to your accountant as soon as possible can help you avoid penalties and interest.
What accounting records should I share with my accountant?
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Bank statements: If you have a business bank account, send the statements to your accountant so they can reconcile your bank and ensure you're including everything you can in your accounts. Also, if you have other accounts, including a deposit or reserve account, these may be useful.
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Loan statements: If you have any business loans, send these and/or details of loan interest to your accountant.
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Finance agreements: Copies of any new agreements taken out in the year, including interest rates and duration are useful for your accountant.
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Business credit card: If you have a business credit card statement, or use your personal credit card occasionally for work expenses, inform your accountant.
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Sales income: Details of all sales invoices raised, copies of all sales invoices if these are recorded on paper. Or give access to your online accounting package.
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Invoices and expenses: Include all purchase invoices and expense receipts for the period.
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Petty cash receipts: Your accountant will need a log of cash expenses, including the petty cash balance at the year-end.
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Payroll records: If your accountant doesn't handle your payroll, you should provide them with a print-out, or digital equivalent, of each month's pay run. Reports should include employees' gross pay, tax and national insurance payments.
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Stock value: Details of the stock valuation at the end of your financial year should be shared with your accountant (if you are a business that holds stock).
Should I use online bookkeeping software?
Advances in cloud accounting means keeping paper records is rarely the best system for you and your business. Moving over to online software is the most efficient way to keep track of your income and expenses. You can also store electronic documentation within the software, attached to the transaction it relates to.
Using a cloud-based software solution also means that when you transition to Making Tax Digital (MTD) for income tax and / or VAT, you will be familiar with using accounting software and may not need to change, or only need a small upgrade to be MTD compatible.
At TaxAssist Accountants Olney we can support clients with QuickBooks, Xero, Dext and for landlords, Hammock, as well as providing you with training to ensure you are happy with how it all works.
How TaxAssist Accountants Olney can help
We can help you complete your tax return accurately so that you can meet the deadline and have already assisted many self-employed individuals and business owners to file theirs. Call us today on 01480 592002 or complete our easy online form to get in touch.
Need support with your tax return?
Contact TaxAssist Accountants for a free, no-obligation consultation to get a fixed fee quote
Or contact usFrequently Asked Questions
The deadline for completing a self-assessment tax return is 31st January, when completing this online. If you want to submit a paper tax return, the deadline is 31st October.
There are lots of benefits to getting ahead with your tax return, to find out more visit our self-assessment pages.
Self-employed individuals, partners in business partnerships and landlords may be required to file a tax return. Those in receipt of child benefit and earning over £60,000 and those earning more than £10,000 in savings and investment income will need to complete a tax return too. For a comprehensive list check HMRC’s content on who must send a tax return.
Last updated 19 May 2026 | First published 17 Dec 2019
This article is intended to inform rather than advise and is based on legislation and practice at the time. Taxpayer’s circumstances do vary and if you feel that the information provided is beneficial it is important that you contact us before implementation. If you take, or do not take action as a result of reading this article, before receiving our written endorsement, we will accept no responsibility for any financial loss incurred.
Helen Wood, CA
Helen is a qualified chartered accountant (CA) and joined TaxAssist in 2025 following three years as a freelance content writer for clients in the tax and accounting publishing sector. Prior to this, She spent 17 years at Big Four and Top 10 accountancy firms. Helen writes clear and helpful articles on tax and accounting for businesses and individuals.
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