Amending your final declaration

If you've found an error in your final declaration after submitting it, you can amend it and resubmit. HMRC will recalculate your tax bill based on the changes.

When to amend your final declaration

Amend your final declaration if you discover errors after it's been submitted to HMRC. This includes:

  • Income you forgot to record
  • Expenses you didn't claim
  • Incorrect figures for allowances or adjustments
  • Mistakes in your property business records that affect the year-end totals

Once you've submitted your final declaration, this is the way to correct any errors - including errors that originated in your quarterly updates.

For errors found before you submit your final declaration, see Amending quarterly updates for how to fix them earlier in the process.

How to amend in Provestor

Amending a final declaration works exactly the same way as submitting it the first time.

To amend your final declaration:

  1. In My taxes, choose My Tax Returns
  2. Choose the tax year you need to amend
  3. Make your corrections to income, expenses, or adjustments
  4. Review your updated figures
  5. Choose Submit

Your amended final declaration replaces the previous one. HMRC receives the corrected figures and recalculates your tax bill.

Time limit for amendments

You can amend your final declaration within 12 months of the statutory filing deadline (normally 31 January).

For example, if your final declaration for the 2024/25 tax year is due by 31 January 2026, you can amend it until 31 January 2027.

After the 12-month window closes, contact HMRC if you discover errors that need correcting.

For full details on amendment time limits, see HMRC's guidance on making updates at the end of a tax year.

Impact on your tax bill

When you submit an amended final declaration, HMRC recalculates your tax bill automatically.

This may result in:

  • A refund if you've overpaid
  • An additional payment if you owe more
  • Adjusted payments on account for the following tax year (if the change is significant)

The recalculation reflects your corrected income, expenses, and allowances. If your profit changes, your tax liability changes too.

Checking your updated tax position

After HMRC processes your amendment, Provestor shows your updated tax calculation.

You can also check in HMRC online services:

  1. Sign in to your HMRC online account
  2. Navigate to Self Assessment
  3. View your updated tax calculation and amount owed

Paying or receiving the difference

If you owe additional tax:

Pay the difference by the original payment deadline (31 January following the end of the tax year) if you're still within that timeframe. If the deadline has passed, pay as soon as possible to minimise interest charges.

See How to pay HMRC for payment methods.

If you're due a refund:

HMRC will process the refund automatically. You can check the status in your HMRC online account.

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