Start with a list of the missing tax years and every HMRC notice. Keep records separate for each year. An outstanding return, an error in a filed return and undeclared income can need different routes, so agree the filing or disclosure plan before submitting figures.
Build a year-by-year list
For each year, record the income sources, HMRC notice, whether anything was filed and which documents are missing. A current return does not automatically settle older years. Keep the notices because they can affect the route and deadline.
Separate three different jobs
- A missing return HMRC issued: establish how that year can be filed.
- A filed return with an error: check the amendment window or later correction route.
- Income never declared: check whether an official disclosure process applies.
For rental income, the Let Property Campaign guide explains a possible disclosure route. It is not a substitute for deciding which years belong on ordinary returns.
Reconstruct the records without copying guesses
Collect bank records, PAYE documents, rental statements, invoices and earlier accountant workings. Mark uncertainty. An invoice date and payment date can fall in different years, so the accounting method matters.
Agree the full work and payment plan
Tax, interest, penalties and payments on account can all affect what is owed. Filing does not automatically cancel a penalty or arrange instalments. Discuss payment difficulty while the figures are established. Ask TaxSimba whether the historic or disclosure work is accepted and get the years, scope and fee agreed before buying a routine current-year service.
Use a recovery table instead of one mixed folder
| Year | Filing position | Evidence gap | Next action |
|---|---|---|---|
| 2023/24 | Return status to confirm | Missing bank period | Obtain statement and check HMRC notice. |
| 2024/25 | Filed, possible error | Omitted income statement | Check correction route and deadline. |
| 2025/26 | Current return to prepare | P60 still needed | Request document while older work is reviewed. |
This is a planning example, not a recommendation to use the same route for each year. Add the HMRC references and person responsible in your own private copy. An urgent current deadline can need attention while the older years are being reconstructed.
Build a year-by-year recovery plan
Illustrative example.
A taxpayer has an unfiled return for one year, an error in a return already filed for another, and rental income never reported for an earlier period. Labelling all three “late returns” can lead to the wrong process being used.
Create a separate line for each year, describing what HMRC requested, what was submitted and what is missing. The accountant can then distinguish preparation, correction and potential disclosure work. The order of work should reflect actual notices and deadlines, not an assumption that the newest year always comes first.
| Check | Practical action |
|---|---|
| Return requested but missing | Identify the notice, year and outstanding filing task. |
| Return filed with an error | Check the correction route and relevant time limits. |
| Income never reported | Ask whether a disclosure process is appropriate for the facts. |
Should I copy the newest year’s figures into older returns?
No. Each year needs its own evidence and the appropriate accounting treatment. Repeated estimates can create further errors.
Does filing settle every charge automatically?
Check the resulting tax, interest, penalties and payment position separately. An appeal or payment arrangement is another task.
Download a checklist for this guide
- Each affected tax year
- HMRC notices and deadlines
- Filed, unfiled or potentially undisclosed position
- Missing income, expense and payment evidence
- Agreed actions, fees and responsible person