Most people do not struggle with Self Assessment because the tax return itself is impossible.
The problem is usually the records behind it.
One receipt is sitting in an email. Another is in a WhatsApp conversation. A bank statement is missing. A mileage note is saved on an old phone. You can access your HMRC account, but the figures you actually need are scattered across several places.
That is when a relatively straightforward tax return becomes stressful.
If you are asking “What records do I need for Self Assessment?”, the short answer is that you need records supporting the income, expenses, tax already paid, reliefs and other information included in your return.
HMRC requires people who complete Self Assessment returns to keep records so the return can be completed correctly, and HMRC may ask to see supporting documents if it checks the return.
This guide explains what you should have ready before filing, including employment documents, self-employment records, business expenses, rental income, bank statements, mileage records, dividends, pension contributions, Gift Aid and other information that may affect your tax position.
Quick Self Assessment Records Checklist
Before you start preparing your tax return, check whether you have:
- Your Unique Taxpayer Reference (UTR)
- Access to your Government Gateway account
- Your National Insurance number
- P60 or P45, where relevant
- P11D if you received taxable employment benefits
- Self-employment income records
- Sales invoices and receipts
- Business expense receipts and invoices
- Bank statements
- Mileage and travel records
- Rental income and property expense records
- Dividend vouchers
- Savings interest statements
- Pension contribution records
- Gift Aid records
- Student or postgraduate loan information, where relevant
- Child Benefit information, where relevant
- Capital gains records if you sold chargeable assets
- Evidence of tax already deducted or paid
- Details of payments on account already made
You will not necessarily need every item. The records required depend on your income and personal circumstances.
If you already have most of the information but want someone to check the position and prepare the return, Accounting People provides Self Assessment accountant support for individuals, sole traders, landlords and business owners.
Useful tip: save or print the checklist above before you begin. It is much easier to identify missing records before you start the return than halfway through preparing it.
Why Good Records Matter for Self Assessment
Your Self Assessment tax return is only as reliable as the information behind it.
Incomplete records can cause several problems.
You might forget taxable income and submit an incorrect return. You could overlook genuine allowable expenses and pay more tax than necessary. You may also struggle to explain a figure later if HMRC asks how it was calculated.
HMRC says records used for Self Assessment can be kept on paper, digitally or within bookkeeping software, but they need to be accurate, complete and readable.
Keeping your records organised also makes filing considerably easier. Instead of searching through a year’s worth of emails, receipts and bank transactions in January, you can work from information that has already been collected and categorised.
That is especially valuable if you are self-employed, a landlord, freelancer, side hustler or have several different sources of income.
1. Personal and HMRC Details
Start with your basic tax information.
You may need:
- Your Unique Taxpayer Reference
- National Insurance number
- Access to your Government Gateway account
- Previous Self Assessment returns, where relevant
- HMRC payment references
- Details of previous payments made to HMRC
- Bank details where a repayment may be due
Do not leave account access until the filing deadline is approaching. Finding that you cannot access your HMRC account when you are ready to file creates an unnecessary delay.
If you need to complete Self Assessment for the first time, you may also need to register with HMRC. HMRC generally requires someone who needs a return and has not filed before, or who needs to reactivate Self Assessment, to notify it by 5 October following the relevant tax year. For the 2025/26 tax year, that date is 5 October 2026.
For more detail on filing dates, see our UK Self Assessment tax return deadline guide.
2. Employment Income Records
If you were employed during the tax year, you may need information showing your employment income and the tax already deducted.
Common documents include:
- P60
- P45 if you left a job
- P11D if you received taxable benefits or expenses
- Payslips where additional information is needed
- Employment income summaries
- Relevant tax code information
Your P60 summarises your pay and tax deducted for the tax year. A P45 records relevant pay and tax information when you leave an employment. A P11D may contain details of taxable benefits provided by an employer.
Having self-employment income does not mean employment income can be ignored. If you had a job alongside your business during the same tax year, the relevant employment information still needs to be considered when preparing your return.
3. Self-Employment Income Records
For a sole trader, accurate business income records are one of the most important parts of Self Assessment.
Depending on how you operate, your records could include:
- Sales invoices
- Customer receipts
- Payment processor reports
- Cash income records
- Bank deposits
- Marketplace or platform reports
- Refunds and cancellations
- Grants or business support payments where relevant
HMRC requires sole traders to keep records supporting the business income and expenses used to prepare their tax return.
You do not necessarily need a complicated accounting system when your business is small, but you do need a clear way of establishing what the business earned and what it spent.
If you specifically need help with a sole-trader return, see our guide to Self Assessment tax returns for sole traders.
4. Business Expense Records
Allowable business expenses can reduce the taxable profit of a self-employed business, so evidence supporting those expenses matters.
Depending on the business, you may need receipts, invoices or other records for costs such as:
- Office costs
- Software subscriptions
- Business phone and internet costs
- Advertising and marketing
- Professional fees
- Insurance
- Bank charges
- Business travel
- Mileage
- Relevant training
- Stock or materials
- Postage and packaging
- Equipment
- Working-from-home costs where applicable
The important point is that a cost must satisfy the relevant tax rules before it can be deducted.
Where something is used partly for business and partly privately, you may need to identify the appropriate business element rather than claiming the entire cost.
For a detailed breakdown, read our guide to allowable business expenses for self-employed people.
Trying to reconstruct expenses from memory in January is a poor record-keeping system. Save the evidence when the expenditure occurs.
5. Bank Statements and Bookkeeping Records
Bank statements are useful, but they will not always explain the full purpose of a transaction.
A statement might show that £250 was paid to a supplier, for example, without showing what was purchased or whether the expenditure was wholly related to the business.
That is why invoices, receipts and bookkeeping notes remain important.
For cleaner records, it helps to:
- Keep business transactions identifiable
- Reconcile income and expenditure regularly
- Save receipts digitally where appropriate
- Label transactions clearly
- Keep sales invoices organised
- Avoid unnecessary mixing of personal and business transactions
- Review unexplained transactions while they are still recent
HMRC allows Self Assessment records to be kept digitally, provided the records remain accurate, complete and readable.
Cloud accounting software can make the process easier where transaction volumes are increasing. Accounting People provides cloud accountancy services to help businesses maintain organised records throughout the year rather than reconstructing everything when a tax deadline approaches.
Making Tax Digital and Digital Records
Record keeping is now even more important for some sole traders and landlords because Making Tax Digital for Income Tax has begun.
If you are required to use MTD for Income Tax, you or your agent must create and store digital records of relevant self-employment and property income and expenses using compatible software.
You must also continue to keep the underlying records or supporting documents used in preparing your tax return, such as invoices and bank statements. HMRC specifically confirms that the MTD digital-record requirement does not replace the normal obligation to retain supporting records.
If MTD applies to you, see our Making Tax Digital for Income Tax support.
You can also check HMRC’s guidance on creating digital MTD records.
6. Rental Income Records
If you receive income from property, you should keep clear records of both the income received and relevant property costs.
Records might include:
- Rent received
- Tenancy agreements
- Letting agent statements
- Mortgage interest statements where relevant to finance-cost relief calculations
- Repairs and maintenance invoices
- Insurance costs
- Service charges and ground rent
- Council Tax where paid by you
- Utility bills where paid by you
- Legal and professional fees
- Replacement domestic item records where relevant
Property tax can become more complicated where there are finance costs, joint ownership, furnished property, overseas property or several rental properties.
Accurate records should therefore be maintained throughout the year rather than assembled retrospectively when the tax return is due.
Landlords can also read about our accounting support for landlords and property owners.
7. Side Hustle Income Records
Side-hustle income is another area where record keeping can easily be overlooked.
You may receive income from activities such as:
- Freelancing
- Tutoring
- Online selling
- Content creation
- Affiliate marketing
- Delivery work
- Dog walking
- Consulting
- Handmade products
- Renting out equipment or space
Even where an activity starts small, keeping records from the beginning makes it considerably easier to establish the tax position if income grows.
Your records might include:
- Income received
- Invoices
- Platform statements
- Bank transactions
- Payment processor reports
- Business expenses
- Receipts
- Dates of transactions
For more detail about when additional income may need to be reported, see our Side Hustle Tax UK guide.
8. Dividend, Savings and Investment Records
If you receive investment income, you may need documents showing the amounts received during the tax year.
Useful records can include:
- Dividend vouchers
- Investment platform statements
- Bank or building society interest statements
- Bond income information
- Foreign income statements
- Capital gains records
If you sold shares, cryptoassets, property or another chargeable asset, you may also need historic information showing items such as acquisition cost, sale proceeds, transaction fees and relevant dates.
Capital gains records can be particularly important because some of the information needed when an asset is sold may relate to a purchase made several years earlier.
Do not rely on being able to recreate that history easily after the asset has been sold.
9. Pension Contributions and Gift Aid Records
Pension contributions and Gift Aid donations can affect the tax calculation in some circumstances.
Records may include:
- Personal pension contribution statements
- Workplace pension information
- Evidence of personal pension payments
- Gift Aid donation records
- Charity donation summaries
These details can be particularly important where tax relief needs to be reflected in the calculation of your tax liability or adjusted net income.
Keeping supporting statements makes it easier to check whether the correct amounts have been taken into account.
10. Student Loan and Child Benefit Records
Some taxpayers will also need information relating to student loans, postgraduate loans or Child Benefit.
Depending on your circumstances, you may need:
- Student loan plan details
- Postgraduate loan details
- Loan repayments already deducted through employment
- Child Benefit received
- Relevant partner information
The High Income Child Benefit Charge can apply where Child Benefit is received and one person’s adjusted net income exceeds the applicable threshold.
For tax years from 2024/25 onwards, the charge begins where adjusted net income exceeds £60,000. The full amount of Child Benefit is effectively recovered through the charge once adjusted net income reaches £80,000 or more.
You can check the current rules through HMRC’s High Income Child Benefit Charge guidance.
Because adjusted net income can be affected by items including pension contributions and Gift Aid, this is an area where keeping complete records matters.
How Long Should You Keep Self Assessment Records?
The retention period depends partly on whether you are self-employed.
If You Are Self-Employed
HMRC says self-employed people must normally keep their business records for at least five years after the 31 January submission deadline for the relevant tax year.
For example, if your 2025/26 online tax return is due by 31 January 2027, the supporting records should normally be retained until at least the end of January 2032.
There are different rules for very late returns.
You can check the full rule in HMRC’s self-employed record-retention guidance.
If You Are Not Self-Employed
If you send your Self Assessment return on or before the deadline and you are not self-employed, HMRC says records should normally be kept for at least 22 months after the end of the tax year the return relates to.
Where the return is filed late, the retention period changes.
See HMRC’s guidance for other Self Assessment records.
The practical rule is simple: do not destroy tax documents as soon as your return has been submitted.
Common Self Assessment Record-Keeping Mistakes
Keeping a Receipt Without Knowing What It Was For
A receipt can support an expense, but you should also be able to identify why the cost related to the business.
Relying Only on Bank Statements
Bank statements prove that a transaction happened, but they may not contain enough information to demonstrate its purpose.
Mixing Personal and Business Transactions
Mixing transactions makes bookkeeping slower and can make it harder to identify the correct business figures.
Forgetting Cash Income
Cash income still needs to be recorded where it forms part of your taxable business income.
Losing Mileage Records
Mileage claims are much easier to support when journeys are recorded at the time rather than estimated months later.
Waiting Until January
Trying to reconstruct an entire year of transactions immediately before the filing deadline increases the risk of missing income, overlooking expenditure and making errors.
Regular record keeping is considerably more efficient.
Self Assessment Records Checklist Before You File
Before submitting your return, ask yourself:
- Have I included all relevant sources of income?
- Do I have evidence supporting the business expenses I am claiming?
- Are my bank statements complete?
- Have I checked employment income and tax already deducted?
- Have I included rental income where relevant?
- Have I checked savings interest and dividends?
- Have I retained relevant mileage records?
- Have I included applicable pension contributions?
- Have I checked Gift Aid donations?
- Have I recorded tax already paid?
- Have I checked payments on account?
- Have I considered capital gains where relevant?
- Have I checked whether student-loan information is required?
- Have I considered Child Benefit where relevant?
- Are my records stored somewhere secure?
- If MTD for Income Tax applies to me, are the required business or property records being maintained digitally?
If you are approaching the filing deadline, also read our Self Assessment tax return deadline guide.
If your tax bill appears higher than expected, our Payments on Account explained guide explains why HMRC may ask for advance payments towards the following year’s tax liability.
How Accounting People Can Help
Self Assessment becomes much easier when the records behind the return are organised.
Accounting People supports sole traders, landlords, freelancers, directors, side hustlers and other taxpayers with the preparation and filing of Self Assessment tax returns.
We can help you:
- Establish which records are relevant to your circumstances
- Organise income and expense information
- Review allowable business costs
- Check tax already deducted or paid
- Prepare and submit the tax return
- Understand payments on account
- Improve your bookkeeping process for future years
- Prepare for Making Tax Digital where applicable
Businesses that need wider ongoing support can also explore our small business accountant services.
If your records are incomplete, disorganised or spread across several systems, dealing with the problem earlier gives you more time to identify missing information before the filing deadline.
Final Thoughts
Self Assessment is not simply about completing boxes on a tax return.
The figures need records behind them.
Keeping clear evidence of income, expenses, tax already deducted, rental income, pension contributions, Gift Aid, investments and other relevant items makes it easier to prepare an accurate return and respond if HMRC later asks about the figures.
The best approach is to maintain records throughout the year rather than waiting until January.
If you are unsure what records you need for Self Assessment in the UK, start with the fundamentals: income, expenses, bank information and tax documents. Then consider whether your own circumstances introduce additional requirements.
Need help preparing your return? Speak to our Self Assessment accountants for practical support with your records and tax return.
Frequently Asked Questions
What records do I need for Self Assessment?
The exact records depend on your circumstances, but you may need evidence of income, business expenses, tax already paid, employment income, rental income, dividends, savings interest, pension contributions, Gift Aid, capital gains and other information relevant to your return.
HMRC requires people completing Self Assessment to keep records that enable them to fill in the return correctly.
Do I need receipts for Self Assessment?
If you are claiming business expenses, you should retain appropriate supporting records such as invoices, receipts and other evidence.
Records can generally be kept on paper or digitally, provided they remain accurate, complete and readable.
Are bank statements enough for Self Assessment?
Bank statements can be useful evidence, but they may not explain the nature or business purpose of every transaction. Keeping invoices, receipts and bookkeeping notes alongside the statements provides a clearer audit trail.
How long do I need to keep Self Assessment records?
If you are self-employed, HMRC normally requires business records to be kept for at least five years after the 31 January submission deadline for the relevant tax year.
If you are not self-employed and file on time, the usual period is at least 22 months after the end of the tax year.
What records do sole traders need to keep?
A sole trader will normally need records supporting business income and expenses. This can include sales records, invoices, receipts, bank transactions, mileage information, payment processor statements and other documentation used to calculate the figures included in the tax return.
Do I need to keep records for side-hustle income?
If your side-hustle income needs to be reported for tax purposes, keep clear records of the income received and relevant expenditure, along with platform statements, invoices, receipts and bank transactions where applicable.
For more information, read our Side Hustle Tax UK guide.
Does Making Tax Digital change the records I need to keep?
For people within MTD for Income Tax, relevant self-employment and property income and expenses must be recorded digitally using compatible software.
HMRC also requires taxpayers to continue keeping the original records or supporting documents used to prepare the tax return, such as invoices and bank statements.
Can an accountant help organise my Self Assessment records?
Yes. An accountant can help identify which information is required, organise the figures needed for the return, review relevant expenses and highlight missing records before filing.
What happens if I do not keep proper records?
Poor or incomplete records can lead to mistakes in a tax return and make it harder to support the figures if HMRC checks them.
HMRC states that penalties can apply where records are not accurate, complete and readable.
