Checking a Self Assessment statement

A Self Assessment statement combines charges, payments, credits and sometimes payments on account for different periods. Match each line to the relevant year and reference before deciding that the total is wrong or that a payment has disappeared.

Check processing dates and the payment reference used. Keep bank confirmation separate from the calculation of tax due, because proof of payment does not establish that the return itself is correct.

Read the account by year and transaction type

Download or retain the relevant statement and identify the dates it covers. Separate tax charges, payments on account, interest, penalties, repayments and credits. A current balance may combine several periods, so it should not be compared with a single return total without understanding the entries behind it.

HMRC explains the relationship between the tax calculation and the Self Assessment bill. ^[1] Use the calculation to understand the liability and the statement to trace charges and settlement. A bank transfer proves that money left an account; it does not by itself explain how HMRC allocated it or whether the underlying return figure is correct.

Match payments using original evidence

For each payment, record the amount, date, account used and reference transmitted. Keep the bank confirmation and distinguish the date instructed from the date processed. If someone else paid on the taxpayer's behalf, obtain the same evidence rather than relying on a message that the transfer was made.

Check whether the reference belongs to the correct person and tax account. A company tax reference or an old saved bank detail can create confusion. Where the payment is not visible as expected, investigate through the official route with the original evidence. Do not amend a correctly prepared return merely to make the account balance resemble the amount that was paid.

Explain changes following a return or amendment

A new return can add the balancing liability and change later payments on account. An amendment may alter an earlier charge or create a repayment position. Keep the submitted calculation and acknowledgement alongside the account entries so the chronology can be followed without assuming every new line represents an additional unrelated tax bill.

Use Amending a submitted tax return where a return figure itself needs correction and Payments on account: planning cash flow to understand payments on account. If several changes occurred close together, prepare a short reconciliation showing the opening balance, new charges, adjustments, payments and closing balance. This gives the adviser a concrete question to resolve instead of a screenshot with only a highlighted total and no explanation of the expected result.

Review credits and repayments carefully

An apparent credit may be available for repayment, allocated against another liability or affected by a pending account update. Identify the nature of the credit and any repayment request already made. Keep the bank destination under appropriate control and verify unexpected requests to change it through a trusted channel.

If a repayment arrives, match it to the relevant statement and record the amount and date. Avoid treating a credit as both money refunded and money still available to settle another charge. Where a repayment is delayed, keep the supporting calculation and correspondence organised so the issue can be followed up without submitting inconsistent repeated requests through several routes.

Investigate interest or penalties separately

Identify the notice, period and stated reason for each additional charge. Compare the relevant filing or payment dates with the evidence rather than assuming a late-looking statement means the original action was late. A payment allocation issue and a genuine late payment may require different responses, even where the visible account initially looks similar.

Ask the adviser to distinguish an account correction, an appeal and a service complaint. Each addresses a different problem and may have a different timetable. Preserve the original notice and record any deadline while the underlying facts are checked. Do not let a general discussion about the account replace a specific action required to protect an appeal position.

For Self Assessment tax return support, provide the statement, filed calculations, payment schedule and a concise explanation of the discrepancy. State what balance you expected and how you reached it. This lets the reviewer test the arithmetic and allocation directly rather than rebuilding the entire history from disconnected screenshots.

After the issue is resolved, retain the updated statement and explanation with the tax file. Check that any payment plan or future instalment instruction reflects the corrected position. A clear closing record prevents the same apparent discrepancy being investigated again when a different adviser reviews the account or when the next return creates a new set of charges.

Illustrative scenario

A taxpayer pays shortly before checking their account. They retain the bank confirmation, compare the reference and review the statement again through the official service before making an unnecessary duplicate payment.

Preparation checklist

• Identify each tax year
• Match payments to references
• Separate advances and balances
• Record unexplained entries