Payments on account can make a Self Assessment payment larger than the balancing tax for the year just filed. Read the statement as separate liabilities and forecast the next year before deciding whether a reduction request is justified.
A lower bank balance is not evidence of a lower tax liability. Consider income changes, tax already deducted and the consequences of reducing payments too far.
Read January's bill as several components
Separate the balancing payment for the completed year from the first payment on account towards the next year. Identify any other charges and payments already credited. The amount due on one date can cover more than one period, so comparing it only with the tax on the return may make a correct statement appear unexpectedly high.
HMRC explains when payments on account arise, their usual January and July dates, and how each instalment is calculated. [1] Check the exceptions against the actual tax position rather than assuming every Self Assessment taxpayer pays them. Keep the calculation and statement together so the taxpayer can see which part settles an established liability and which part advances payment towards a later calculation.
Build a forecast from income and deductions
List the expected income sources for the year covered by the payments on account. Include material changes in trading profit, property income, employment, pensions or investment income where relevant. Distinguish turnover from taxable profit and identify tax expected to be deducted at source. A business's current bank balance is a cash indicator, not a complete estimate of its personal tax liability.
Use evidence for significant assumptions. An ended contract, retirement date or signed employment agreement may support a change; a hope that business will slow down is less reliable. Keep the forecast separate from the filed return and label it with the preparation date. Revisit the estimate when a major assumption changes, especially after a stronger trading period or an unexpected taxable receipt.
Consider a reduction with its consequences
Where the expected liability is lower, HMRC provides a process for claiming a reduction in payments on account. An excessive reduction can lead to interest on the shortfall. [1] Ask the adviser to compare the proposed payments with a supportable estimate, rather than reducing them to an amount that simply fits the available cash.
Record why the reduction is justified and which assumptions could make it insufficient. A cautious forecast can include more than one scenario, showing the effect of uncertain receipts or costs. If the eventual liability rises, consider the appropriate next action promptly. A reduction request does not change the tax properly due for the year; it changes the advance payments based on the estimate supplied.
Separate a cash problem from a calculation problem
If the payments appear correctly calculated but funds are unavailable, identify the expected receipts, essential outgoings and amount that can realistically be paid. Discuss HMRC's payment support through the appropriate official route. Do not assume that filing a return, requesting a reduction or making a small partial payment creates an agreed instalment arrangement.
Use Time to Pay: information to prepare for preparing information about Time to Pay and Checking a Self Assessment statement for reconciling the Self Assessment statement. Keep evidence of any agreed arrangement and distinguish it from an application or conversation that has not produced agreement. The taxpayer needs a clear view of both the outstanding liability and the action required under the arrangement, including any future tax falling due separately.
Plan savings and review points through the year
Set aside funds using a forecast that reflects the actual sources and timing of income. A fixed percentage of every receipt may be a useful starting habit, but it can be misleading where tax has already been deducted, profit margins vary or other income changes the overall calculation. Review the approach with the accountant rather than treating the percentage as a tax rate.
Put the next statement review and payment dates in the calendar with a named person responsible. After a payment, retain the bank evidence and check allocation to the intended account and liability. Keep the reference used, amount and date so an apparent missing credit can be investigated without searching several personal and business accounts.
For Self Assessment tax return support, provide the filed calculation, current statement, payment history and forecast assumptions. Ask for a breakdown of what is due and whether a reduction or separate payment discussion is appropriate. Agree when the forecast will be revisited. This helps avoid both an unnecessary cash strain from an outdated estimate and an interest-bearing shortfall caused by reducing payments without a reasoned calculation.
Illustrative scenario
A consultant has a strong first year followed by a quieter contract pipeline. They prepare a documented forecast and ask whether the next payments can be reduced, keeping a reserve if work increases again.
Preparation checklist
- Separate balancing tax
- Identify each advance payment
- Prepare an income forecast
- Review reductions during the year
Frequently asked questions
Why is my January amount larger than the tax on my return?
It may include a payment on account for the following year as well as the balancing liability. Reconcile each component and any existing credits before deciding the total is incorrect.
Can I reduce payments because business cash is tight?
A reduction should reflect the expected tax liability, not merely the bank balance. If the liability is unchanged, discuss payment support separately through HMRC's appropriate process.
What happens if I reduce the payments too much?
Interest can arise on the shortfall. Keep a supported estimate, review changing circumstances and ask the adviser what action is appropriate if the expected liability increases.
Does paying early remove the need to file?
No. Payment and filing are separate obligations. Retain evidence of both the accepted return and the allocation of payments to the correct Self Assessment account.
Official sources
Sources checked: 8 September 2026. Check the linked guidance for subsequent changes.
General information only. The appropriate action depends on your circumstances and the applicable jurisdiction.
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