What your accountant needs to file your tax return

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?

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.
Loan statements: If you have any business loans, send these and/or details of loan interest to your accountant.
Finance agreements: Copies of any new agreements taken out in the year, including interest rates and duration are useful for your accountant.
Business credit card: If you have a business credit card statement, or use your personal credit card occasionally for work expenses, inform your accountant.
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.
Invoices and expenses: Include all purchase invoices and expense receipts for the period.
Petty cash receipts: Your accountant will need a log of cash expenses, including the petty cash balance at the year-end.
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.
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 Hounslow Centre 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 Hounslow Centre 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 0800 0523 555 or complete our easy online form to get in touch.

Need support with your tax return?

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Last updated: 19th May 2026