Accuracy requirements

Quarterly updates are estimates and check-ins — not the final word on your tax.

• No quarterly tax payments: updates are reporting only. Tax is still due on the usual Self Assessment schedule: balancing payment by 31 January and second payment on account by 31 July.
• Estimates are fine: use best estimates each quarter. Depreciation, accruals, and capital allowances belong in your year-end tax return, not in quarterly updates.
• Perfect accuracy is not required: harmless rounding or timing differences are expected. Only final figures after year-end adjustments determine the tax you owe.
• No declaration yet: there is no signed declaration on a quarterly update, and inaccuracy penalties do not apply to quarterly reports. Errors that carry through to your final tax return can still be reviewed.
• Use real digital records: totals should come from your maintained digital records. The goal is consistency — each update builds on the last.

In summary, quarterly updates are a practical way to keep HMRC informed and catch mistakes early. They do not change how your final tax is worked out — that still happens when you submit your tax return after year-end adjustments.

For jointly owned property, income splits, or simplified expense rules, see the Joint property owners guide. HMRC's official Send quarterly updates guidance has further examples.