An MTD estimate is not necessarily your final liability or the balance left to pay. Missing income, reliefs, year-end adjustments and tax already deducted can change those figures. Use it for planning, then check the final calculation and HMRC account.
What the estimate can include
HMRC uses the self-employment and property figures reported so far, together with other information it already holds. Depending on your software, additional income may also be supplied during the year. Information that has not yet been reported can leave the estimate incomplete.
For example, a landlord may also have employment income, savings interest and dividends. A property update alone does not tell the whole story. If part of that wider income is missing, the estimate may not reflect the tax band that eventually applies.
Year-end adjustments can change the result
Quarterly updates summarise records; they do not require all the accounting and tax adjustments needed for the annual return. Business-use adjustments, reliefs and other year-end calculations can change the final liability. An accounting year that differs from the tax year may also make an interim estimate less straightforward.
Avoid taking money out of your tax savings account solely because a screen shows a lower figure than expected. Ask your accountant which assumptions sit behind it and whether anything important is missing.
Tax liability and amount still to pay differ
An estimated liability is not necessarily the outstanding balance after payments, credits or payments on account. Check which figure you are looking at. The annual calculation and HMRC account need to be reconciled before deciding what remains payable.
Make the estimate more useful
Keep business records current and tell your accountant about other income, changes in employment, pensions, student loans and significant one-off transactions. Explain unusual entries rather than allowing an incorrect category to carry forward.
TaxSimba's accountant can review the figures available within the agreed service and explain what further information is needed. Use the estimate to support sensible planning, while keeping the final return, the payment position and the service subscription fee clearly separate.
Explain the difference between three tax figures
Illustrative preparation example.
Your software shows an in-year estimate, the draft annual calculation shows another amount and the HMRC account shows a balance after payments. Compare their dates and what they include. They can describe different stages rather than a single unexplained software error.
Check: Which figure is an estimate, which is total liability and which is still payable?
| Check | Practical action |
|---|---|
| What information underlies the estimate? | Check reported business figures and any other income or reliefs already included. |
| Which year-end adjustments are outstanding? | Identify business-use, accounting and tax adjustments before treating the figure as final. |
| Is the screen showing liability or balance due? | Reconcile payments, credits and dated charges separately. |
Can an estimate change even if quarterly records were accurate?
Yes. Other income, reliefs and year-end adjustments can affect the final result.
Does an estimated bill mean tax is payable every quarter?
No. Reporting and payment rules are separate. Check the actual HMRC statement and payment dates.
Download a checklist for this guide
- Record the estimate's date and period.
- List information included and missing.
- Identify outstanding year-end adjustments.
- Reconcile prior payments and tax credits.
- Review the reserve against the completed annual calculation.