You can correct a Self Assessment return after you have submitted it, whether the mistake increases or reduces your tax. The route depends on how long ago the filing deadline passed. Within the normal window you change the return itself; after it, you write to HMRC or make a formal disclosure. For UK sole-trader drivers, a correction is one stage of the wider Self Assessment process for Uber and private hire drivers, and it starts with working out which route applies.
The timing matters this winter. In early 2026 HMRC wrote to some people whose 2024 to 2025 returns included provisional or round-sum figures, asking them to check and amend, according to the Low Incomes Tax Reform Group’s summary of those letters. The normal window for changing a 2024 to 2025 return closes on 31 January 2027.
Which Correction Route Applies
HMRC’s guidance on changing a return lets you correct a return within 12 months of the Self Assessment deadline. LITRG’s amendment guide adds that if your notice to file was issued after 31 October, the window runs for 15 months from the date of the notice. Find your situation in the table before gathering anything else.
| Your situation | Route | Time limit |
|---|---|---|
| 2024 to 2025 return filed by 31 January 2026 | Amend online, through your software or with corrected paper pages | Usually 31 January 2027 |
| Notice to file issued after 31 October | Amend the return in the same way | 15 months from the date of the notice |
| 2023 to 2024 or earlier, too little tax paid | Write to HMRC with the year, the reason, the amount and your signature | Outside the normal window; HMRC may ask for a formal disclosure |
| 2023 to 2024 or earlier, too much tax paid | Claim overpayment relief in writing | Up to 4 years after the end of the tax year |
You can amend a return more than once before the deadline. LITRG notes that an amendment, whether by you or HMRC, extends the period in which HMRC can open an enquiry into that return, so check the corrected figures once and get them right.
Amending Online, Through Software or on Paper
If you filed through HMRC’s online service, wait 72 hours after filing, sign in, open your Self Assessment account and go to the tax return options for the year you want to change. Make the corrections and file the return again. If you or your accountant used commercial software, the change goes through that software; HMRC says to contact the provider for help, and to contact HMRC if the software cannot make corrections.
For a paper return, send the corrected pages to the address on your Self Assessment paperwork. Write ‘amendment’ on each page and include your name and Unique Taxpayer Reference.
For a year outside the window, HMRC asks for a letter giving the tax year you are correcting, why you think you paid too little, how much you think you underpaid and your signature. An overpayment relief claim has stricter content rules, including a signed declaration that the details are correct and complete, and HMRC says it will reject a claim that leaves out the required information. Where several older years have undeclared income, HMRC may point you to its digital disclosure route rather than a letter.
Common Driver Errors Worth Checking
- A second app or a few weeks of statements missing from turnover.
- Net payouts entered as turnover, with platform fees then deducted again, which understates profit.
- Tips and bonuses paid through the app left out because they were never separated in the bank records.
- Fuel, insurance or repairs claimed on top of the simplified mileage rate, which already covers them.
- A phone or other mixed-use cost claimed in full instead of the business share.
- Provisional figures used at filing and never replaced with the final amounts.
- A cost missed entirely, such as licence fees or accountancy, which would reduce the bill.
Gather the evidence for each item before changing anything. The Uber driver Self Assessment document checklist lists the statements, invoices and logs a complete return relies on. A change of vehicle method needs checking against your earlier claims for that car before you amend.
Before-and-After Reconciliation
Set the return as filed beside the corrected figures, one line at a time, with the evidence for every change. The example below is fictional and shows the method only. It assumes a sole trader in England, a 2024 to 2025 return and 15,600 business miles at the 2024 to 2025 simplified rates of 45p for the first 10,000 miles and 25p after that.
| Return line | As filed | Corrected | Change | Evidence |
|---|---|---|---|---|
| Uber fares before fees | £36,000 | £36,000 | None | Uber annual summary and weekly statements |
| Bolt fares before fees | £0 | £2,400 | +£2,400 | Bolt statements found after filing |
| Platform fees | £7,200 | £7,800 | +£600 | Bolt fee invoices |
| Simplified mileage | £5,900 | £5,900 | None | Mileage log |
| Fuel | £2,100 | £0 | −£2,100 | Already covered by the mileage rate |
| Phone | £600 | £420 | −£180 | 70% business share from a usage log |
| Taxable profit | £20,200 | £24,280 | +£4,080 | Arithmetic of the lines above |
Profit rises by £4,080. In this example the whole increase falls in the basic rate band and above the Class 4 threshold, so the extra Income Tax at 20% is £816 and the extra Class 4 National Insurance at 6% is £244.80, a total of £1,060.80 before interest. Scottish rates, other income and reliefs all change how much tax a driver pays, so treat this figure as an illustration. A correction can equally reduce the bill: a missed licence fee works in the driver’s favour.
What Happens to Your Bill
After an online amendment you see the amended bill straight away. Within three days your HMRC statement shows the difference and any interest, and where more is due, the payment deadline and the effect on your payments on account. LITRG says interest runs from the original due date until you pay, and the next payments on account rise as well. HMRC’s interest rates page sets late payment interest at the Bank of England base rate plus 4%, listed as 7.75% from 9 January 2026. If you overpaid, HMRC repays the difference once the amendment is processed.
A careless error can carry a penalty as well as interest. HMRC’s inaccuracy penalties factsheet says there is no penalty if you took reasonable care, and that the range for a careless error is 0% to 30% when you disclose it before HMRC has reason to know about it, against 15% to 30% once it is prompted. HMRC can reduce a careless penalty to nil only on an unprompted disclosure, which is a reason to correct a known error promptly.
Amendment Preparation Checklist
- Identify the tax year, the date you filed and the date on your notice to file, then confirm which route in the table applies.
- Download the return as filed, its tax calculation and the submission receipt.
- List every line you think is wrong and attach the statement, invoice or log that supports the corrected figure.
- Complete a before-and-after reconciliation and check the arithmetic of the new profit.
- Check whether the change affects payments on account for the following year.
- Record whether any HMRC letter or compliance check already covers the year, and note its reply-by date.
- Agree who submits the amendment, then save the new receipt and calculation with the original.
- Set aside the extra tax and interest, or note the refund you expect and check that it arrives.
Help With a Corrected Return
If the correction spans more than one year, changes your vehicle method or sits outside the normal window, our Uber tax returns service can review the filed return, prepare the reconciliation and submit the amendment within an agreed scope. Tell us the tax years, how you filed and whether HMRC has written to you when you ask for a fixed quote.
Official sources checked 22 October 2026. The table, reconciliation and tax figures are illustrations for UK sole-trader drivers in England, Wales or Northern Ireland. Making Tax Digital quarterly updates, VAT returns and company accounts are corrected through separate processes.
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