Self Assessment reminder letter templates for your clients (2025/26)
Written by the Mipp team
Published: 8 October 2026 | Last checked against GOV.UK: 8 October 2026 | Accurate as of October 2026
Here are five Self Assessment reminder letter templates for UK practices, one for each stage from the first records request to the final notice before the 31 January 2027 deadline. Copy them, replace the text in square brackets and send them from your own email or on your letterhead. There is also a records checklist by client type to attach to the first request.
When to send each reminder
The online deadline for 2025/26 returns is 11:59pm on 31 January 2027, which is a Sunday (GOV.UK). Work back from Friday 29 January 2027 so clients, banks and your own team are not relying on the weekend. The timing follows the week-by-week Self Assessment season plan. Wider dates are in HMRC deadlines for 2026/27.
| Step | Suggested send date | Who gets it | Goal |
|---|---|---|---|
| 1. Records request | By late October 2026 | Every Self Assessment client | Records in by your records date |
| 2. Friendly chaser | Mid November 2026 | Anyone whose records are not in | A gentle nudge with the checklist again |
| 3. Records cut-off chaser | Early December 2026 | Anyone still outstanding | A firm date and what happens after it |
| 4. Final notice | First week of January 2027 | Anyone still outstanding | Last chance before the deadline |
| 5. Approval and payment reminder | When each return is ready, and by mid January at the latest | Every client with a finished return | Approval, then payment on time |
Adapt the dates to your own capacity. If you charge for late records or move late clients to a later slot, say so only if it is in your engagement letter.
Template 1: Self Assessment records request
Subject: Your 2025/26 tax return: please send your records by [records date]
Dear [Client first name],
It is time to prepare your Self Assessment tax return for the 2025/26 tax year (6 April 2025 to 5 April 2026). The deadline for filing online is 31 January 2027, and any tax you owe for 2025/26 is due by the same date.
To give us time to prepare your return and go through it with you, please send us your records by [records date, for example Monday 30 November 2026].
I have attached a checklist of what we usually need. Please send whatever applies to you, and tell us about anything new this year, such as a new source of income, a property bought or sold, or a change in your circumstances.
You can send your records by [your secure upload method, email address or postal address].
If nothing has changed since last year, a quick reply saying so, together with the documents on the checklist, is all we need.
If you have any questions, reply to this email or call me on [phone number].
Kind regards, [Your name] [Practice name] [Phone number]
Short version for clients whose affairs rarely change
Subject: Quick check for your 2025/26 tax return
Dear [Client first name],
Your 2025/26 tax return is due by 31 January 2027. Has anything changed since last year? If not, please send the items on the attached checklist by [records date] and we will take it from there.
Kind regards, [Your name]
Template 2: friendly chaser
Subject: Reminder: records for your 2025/26 tax return
Dear [Client first name],
A quick reminder that we are still waiting for your records for your 2025/26 Self Assessment tax return. We asked for them by [records date].
Sending them now means we can prepare your return well before the January rush and give you plenty of notice of any tax to pay. I have attached the checklist again.
If anything is holding you up, or you are not sure what to send, just reply and we will help.
Kind regards, [Your name] [Practice name]
Template 3: records cut-off chaser
Subject: Action needed: your 2025/26 tax return records by [cut-off date]
Dear [Client first name],
We have not yet received the records we need for your 2025/26 Self Assessment tax return.
To make sure we can file your return before the 31 January 2027 deadline, we need everything by [cut-off date, for example Friday 18 December 2026].
[Include only if it is in your engagement letter: Records received after [cut-off date] will be dealt with in date order and may incur our late records fee of [amount], as set out in our engagement letter.]
If you already know some items will be late, please send what you have now and tell us what is missing. That lets us start on the rest.
Kind regards, [Your name] [Practice name]
Template 4: final notice before the deadline
Subject: Final reminder: your tax return deadline is 31 January 2027
Dear [Client first name],
This is our final reminder about your 2025/26 Self Assessment tax return. We still need [list of outstanding items, or "your records"] to complete it.
The online filing deadline is 31 January 2027. If a return is filed late, HMRC charges an initial £100 penalty, with further penalties the longer it is late, and separate penalties and interest if tax is paid late (GOV.UK).
Please send the outstanding items by [date, for example Friday 15 January 2027] so that we can prepare your return and give you time to check and approve it.
If you cannot meet this date, please call me on [phone number] so we can agree what to do.
Kind regards, [Your name] [Practice name]
Template 5: approval and payment reminder
Subject: Your 2025/26 tax return is ready to approve
Dear [Client first name],
Your 2025/26 Self Assessment tax return is ready. Please check the attached copy and reply to confirm you are happy for us to file it, ideally by [approval date, for example Wednesday 27 January 2027].
Based on this return, the amount due to HMRC by 31 January 2027 is £[amount]. [Include if relevant: This is made up of £[amount] for 2025/26 and a first payment on account of £[amount] towards your 2026/27 bill. A second payment on account of £[amount] is due by 31 July 2027.]
Because 31 January 2027 is a Sunday, if you pay by cheque or Bacs, your payment needs to reach HMRC by Friday 29 January 2027. Payments by Faster Payments (online or telephone banking) or by debit or corporate credit card can still be made over the weekend (GOV.UK). Bacs payments usually take 3 working days, so allow time.
[Payment reference and how to pay: your 11-character payment reference is your 10-digit Unique Taxpayer Reference followed by the letter K. Full payment options are on GOV.UK.] https://www.gov.uk/pay-self-assessment-tax-bill
If you have any questions about the figures, please call me on [phone number] before approving.
Kind regards, [Your name] [Practice name]
Self Assessment checklist: what to ask clients for
Attach this to Template 1. Ask for what applies to each client, not everything on the list.
Every client
- Unique Taxpayer Reference (UTR) and National Insurance number, if you do not already hold them
- Any letters from HMRC received since the last return
- Details of anything new: income sources, property, changes of address or circumstances
- Bank and building society interest for the year
- Dividends received, including from their own company
- Pension contributions paid personally
- Gift Aid donations
- Child Benefit received in the household, if their income may be over the High Income Child Benefit Charge threshold
- Student loan or postgraduate loan plan type, if repaying
- Details of any shares, property or other assets sold (for Capital Gains Tax)
Sole traders
- Sales and income records for the business year
- Business expenses, with receipts or a summary by category
- Bank statements for the business account
- Details of equipment or vehicles bought or sold
- Mileage records, if claiming mileage
- Any CIS payment and deduction statements, if working in construction
Landlords
- Rent received for each property
- Letting agent statements
- Property expenses: repairs, insurance, agent fees, ground rent and service charges
- Mortgage interest statements
- Details of any property bought or sold
Company directors
- P60 from the company
- P11D, if they received benefits in kind
- Dividend vouchers or a summary of dividends paid
- Any director's loan account details you need
Partners
- Their share of the partnership's profit or loss for the year, from the partnership return
Employees and pensioners with other income
- P60 for the tax year, and P45 if they changed jobs
- P11D, if they received benefits in kind
- State Pension and private pension statements
- Records of the other income that brings them into Self Assessment
Clients who may need Making Tax Digital next year
Sole traders and landlords with qualifying income over £30,000 for 2025/26 (turnover from self-employment and property, before expenses) will need to use Making Tax Digital for Income Tax from 6 April 2027 (GOV.UK). It is worth mentioning this in Template 5 for those clients.
How to know who still needs a reminder
Sending the right template to the right client is the hard part. The simplest method is to keep every client's return at a stage:
- Waiting on client: records not yet in. These clients get Templates 2, 3 and 4.
- With client: return sent for approval. These clients get Template 5 and a follow-up if they do not reply.
In Mipp's Compliance view, the Self Assessment tab lists each client's return with these stages (To do, In progress, Waiting on client, With client, Signed, Submitted). You can see what is overdue or due this week, and move several returns to a new stage at once after a round of chasers. Mipp does not send emails to your clients: you send these templates from your own inbox, and Mipp keeps track of who is still waiting.
Frequently asked questions
When should I send the first Self Assessment reminder to clients?
In October, with a clear records date and the checklist attached. That leaves November and December for preparing returns and January for approvals and the last few returns.
How many reminders should a practice send?
Five steps cover most clients: a records request, a friendly chaser, a cut-off chaser, a final notice and an approval and payment reminder. Clients who send records promptly only ever see the first and last.
What records does a client need for a Self Assessment return?
It depends on their income. Use the checklist above: every client, then the section for sole traders, landlords, directors, partners or employees and pensioners with other income.
Should a reminder mention HMRC penalties?
Briefly and factually. For a 2025/26 return filed late, HMRC charges an initial £100 penalty, with more if it is later still, and separate penalties and interest for paying late (GOV.UK).
Can I charge clients who send their records late?
Only if your engagement letter says so. Template 3 has an optional line for this; delete it if it does not apply.
What should clients know about paying on a Sunday deadline?
If they pay by cheque or Bacs, the payment must reach HMRC by Friday 29 January 2027. Faster Payments and card payments can be made over the weekend (GOV.UK).
How do I set up reminders for business tax return and payroll deadlines?
In Mipp, enter each client's details once (entity type, year end, VAT details, payroll frequency, CIS and auto-enrolment) and Mipp works out the next 12 months of deadlines from them. That covers CT600 filing, annual accounts and the confirmation statement, VAT returns, payroll runs with the FPS due on or before payday, P60s, P11Ds, CIS returns, pension contributions and auto-enrolment re-declarations. The dates for contributions, the declaration and re-enrolment are set out in pension auto-enrolment deadlines. The dates appear in the Compliance view, grouped into Overdue, Due this week, Due this month and Later, and on each client's Compliance tab. These reminders are a view you check, not alerts: to see the dates in your diary too, subscribe to Mipp's private calendar feed in Google, Outlook or Apple calendars. Mipp does not create tasks for PAYE or Corporation Tax payments, does not email your clients and does not file anything with HMRC or Companies House. See how this works in Mipp's practice management software for accountants.
Know who still owes you records
Know exactly who still owes you records. Try Mipp's Compliance view free for 14 days. Plans start at £19 a month for one person; see pricing.
See how Mipp helps you track every client's Self Assessment return, or how it works as a CRM for bookkeepers.
Sources
All checked on 8 October 2026. Accurate as of October 2026.
- GOV.UK, Self Assessment tax returns: deadlines. https://www.gov.uk/self-assessment-tax-returns/deadlines
- GOV.UK, Self Assessment tax returns: penalties. https://www.gov.uk/self-assessment-tax-returns/penalties
- GOV.UK, Pay your Self Assessment tax bill (weekend rule, payment methods and timings). https://www.gov.uk/pay-self-assessment-tax-bill
- GOV.UK, Understand your Self Assessment tax bill: payments on account. https://www.gov.uk/understand-self-assessment-bill/payments-on-account
- GOV.UK, Find out if and when you need to use Making Tax Digital for Income Tax. https://www.gov.uk/guidance/find-out-if-and-when-you-need-to-use-making-tax-digital-for-income-tax