PingtailUK Self Assessment client document checklist
What to ask a client for before you prepare a Self Assessment return: income, property, pensions, gains and the reliefs people forget, with typical dates.
A Self Assessment return is only as good as the paperwork behind it, and the paperwork is spread across a client's life: a P60 from the employer, interest from three banks, a letting agent's annual statement, a pension contribution made in March, a share sale nobody mentioned. Clients do not think of these as one set. They send what is in the kitchen drawer and assume that is everything.
This checklist groups what to ask for by source of income and by the reliefs clients forget, with the typical dates that decide when each document exists. It is written for UK firms preparing individual returns for employees with extra income, sole traders, landlords and investors. The rules change from year to year, so treat the dates as typical and check the current rules for your client.
The dates that shape the year
The tax year runs from 6 April to 5 April. These are the deadlines HMRC publishes for a typical return. When a date falls on a weekend the rule can differ, so check the current rules for your client.
| Date | What it means |
|---|---|
| 5 April | The tax year ends. |
| 31 May | Employers must give a P60 to anyone working for them on 5 April, on paper or electronically. |
| 31 July | Second payment on account for the year just ended, for clients who make them. |
| 5 October | Deadline to tell HMRC a return is needed, for a client who has not sent one before or did not need to last year. |
| 31 October | Paper returns must reach HMRC. |
| 30 December | Online returns sent by this date can have the tax collected through the client's tax code, where that applies. |
| 31 January | Online returns due, the balance of tax due, and the first payment on account for the current year. |
Payments on account are two advance payments toward the next bill, each half of last year's tax, due by 31 January and 31 July. They are not needed if the client owed less than £1,000 last year, or paid more than 80% of their tax at source, for example through their tax code.
When to ask for what
Most documents for the year exist by early June, once P60s are out. That makes the summer the best time to collect, long before the January rush. A practical schedule for a small firm:
- Mid-April: send each returning client their own list, built from last year's return. Ask for anything that already exists: bank interest, rental statements, self-employed records.
- Early June: follow up for P60s and anything still missing.
- September: a firm internal deadline for documents, with a reason: "so your return is done well before the winter".
- November and December: chase the stragglers by name. Calls for anyone after three written reminders.
- Early January: a final cut-off, after which the client's return is prepared on what you have or the client is told plainly what is at risk.
The year-end document collection plan turns this into a month-by-month routine for the whole firm.
The basics for every client
- Their Unique Taxpayer Reference (UTR) and National Insurance number, if you do not hold them.
- Any letters from HMRC since the last return, including tax code notices and statements.
- Payments on account already made for the year, with dates.
- Changes in their life: a new job, a move, a marriage or separation, a child, starting or stopping a business, letting a property, moving abroad.
- Bank details for any repayment.
Employment and benefits
- The P60 for every job held on 5 April.
- The P45 for any job that ended during the year.
- Details of benefits in kind, such as a company car or medical insurance, from the P11D or the employer, if any.
- Expenses paid personally for work and not reimbursed, with receipts.
- Tips or other employment income not shown on the P60.
Ask for the P60 by name and say where it comes from: "the P60 your employer gives you by the end of May, often on the payroll site". Clients confuse it with a payslip.
Self-employment
- Sales invoices or a takings record for the year, including cash.
- Bills and receipts for business expenses.
- Full bank statements for every account used for the business.
- Mileage records if the client uses their own vehicle for work.
- Details of equipment bought, with dates and costs.
- If they work from home, the costs you will need to work out a claim.
Sole traders whose income is high enough may now be sending quarterly updates under Making Tax Digital for Income Tax. For them most of these records arrive through the year; see collecting quarterly records for Making Tax Digital.
Property income
- The letting agent's statements, or the client's own record of rent received, for each property.
- Bills for repairs, maintenance, insurance, agent fees and ground rent or service charges.
- The mortgage interest statement for each property.
- Dates of any property bought, sold or first let during the year.
- Any rent from a room in the client's own home.
Ask for statements that cover the tax year, 6 April to 5 April. Letting agents and lenders often issue annual statements on the calendar year, and a client who sends those will leave three months out.
Savings, dividends and investments
- Interest statements from every bank and building society account, for the tax year.
- Dividend vouchers or the dividend summary from the platform.
- The consolidated tax certificate or annual tax summary from any investment platform or fund manager.
- Details of any income from abroad.
Pensions
- The State Pension amount for the year, if the client receives it.
- P60s from any private or workplace pension being paid out.
- Personal pension contributions the client paid themselves, with the provider's statement.
- Any lump sum taken from a pension during the year.
Capital gains
- For a property sale: the completion statements for the purchase and the sale, and bills for improvements.
- For shares or funds: the contract notes or platform report for each sale, and the purchase cost.
- For other assets: what was sold, when, for how much, and what it cost.
Gains are the item clients mention last. Ask the question directly in the first email: "Did you sell any property, shares, funds or other valuable items between 6 April and 5 April?"
Reliefs and charges clients forget
- Gift Aid donations: the charities and amounts.
- Child Benefit received by anyone in the household, which can lead to a charge at higher incomes.
- Student loan or postgraduate loan repayments, and the plan type.
- Marriage Allowance transfers.
- Payments into a pension that may bring extra relief.
Each of these is a yes or no question before it is a document. Put the questions in the request so the client answers them in one place.
The printable checklist
Send each client only the sections that apply to them, based on last year's return and the answers to the life-change question. A landlord with no employment does not need the employment section, and a short list gets sent faster than a long one. For how to word the email itself, see how to write a document request email clients actually answer. For a new client, start with the basics and their identity documents; see collecting identity documents from new clients.
- Basics: UTR, National Insurance number, HMRC letters, payments on account made, life changes
- Employment: P60, P45, benefits in kind, unclaimed work expenses
- Self-employment: income, expenses, bank statements, mileage, equipment
- Property: rent, bills, mortgage interest, purchases and sales
- Savings and investments: interest, dividends, platform tax summaries, foreign income
- Pensions: State Pension, pension P60s, personal contributions, lump sums
- Capital gains: sale and purchase records
- Reliefs and charges: Gift Aid, Child Benefit, student loan, Marriage Allowance
Questions
When is the best time to ask clients for Self Assessment documents?
Start in April with what already exists, and follow up in early June once employers have issued P60s. Most documents for the year exist by then. Collecting over the summer leaves the autumn for preparation and keeps January for the last few clients, not the majority.
Should I ask for statements on the tax year or the calendar year?
On the tax year, 6 April to 5 April, and say so in every item. Many banks, lenders and letting agents produce calendar-year summaries. A client who sends those leaves out the first quarter of the year, and you only notice when the figures do not reconcile.
What if a client does not have their P60?
Ask them to request a replacement from the employer. If that is not possible, the same figures can be found in the client's personal tax account or the HMRC app, or by contacting HMRC. Tell the client which one to try first so they do not stall.
Do clients in Making Tax Digital still need a Self Assessment checklist?
Yes, for everything outside their self-employment and property records. Interest, dividends, pensions, gains, Gift Aid and Child Benefit still go on the tax return, which is still due by 31 January. Their quarterly records simply arrive through the year instead of all at once.
Doing this with Pingtail
Pingtail has a ready-made United Kingdom checklist for the individual return, and you can remove what a client does not need, add what they do, and save it as your own template. Each item tells the client what to send and where to find it, reminders list only what is still missing, and every upload is checked, so a statement for the wrong tax year is flagged while the client is still on the page. The page for tax preparers shows how a season runs. You can try it on yourself first: send a test request to your own email and upload the wrong file on purpose.