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Estimate a Self Assessment reserve, balancing payment and Payments on Account from your inputs. Confirm amounts and dates against your HMRC statement.
Suggested monthly reserve
£648.79/mo
Annual combined liability
£9,731.80
Income Tax, NI, CGT and student loan
Total to reserve
£9,731.80
Combined liability / self-employed profit: 19.46%
Balancing payment
£9,731.80
Due 31 Jan 2028
First POA
£0.00
Due 31 Jan 2027
Second POA
£0.00
Due 31 Jul 2027
No Payments on Account are included from the information entered. Check your HMRC statement for your actual obligation and pay any balancing amount by its due date. Your current reserve is below the £9,731.80 planning target. This is a cash gap indicator, not a penalty prediction. Check your HMRC statement and payment options.
Adjust your assumptions to see how your tax reserve changes
Adjust the sliders above to compare an additional profit or pension contribution with the current estimate.
For the 2026/27 liability year. Past-due POAs are excluded; check your HMRC account for unpaid amounts.
| Payment | Amount |
|---|---|
| Balancing payment — 31 January 2028 | £9,731.80 |
As of 2026-10-10. Assumes one deposit per month before any payments due that month, with no interest or withdrawals. Monthly deposit: £648.79.
| Month | Deposit | Payments due | Projected cash |
|---|---|---|---|
| Nov 2026 | £648.79 | £0.00 | £648.79 |
| Dec 2026 | £648.79 | £0.00 | £1,297.58 |
| Jan 2027 | £648.79 | £0.00 | £1,946.37 |
| Feb 2027 | £648.79 | £0.00 | £2,595.16 |
| Mar 2027 | £648.79 | £0.00 | £3,243.95 |
| Apr 2027 | £648.79 | £0.00 | £3,892.74 |
| May 2027 | £648.79 | £0.00 | £4,541.53 |
| Jun 2027 | £648.79 | £0.00 | £5,190.32 |
| Jul 2027 | £648.79 | £0.00 | £5,839.11 |
| Aug 2027 | £648.79 | £0.00 | £6,487.90 |
| Sept 2027 | £648.79 | £0.00 | £7,136.69 |
| Oct 2027 | £648.79 | £0.00 | £7,785.48 |
| Nov 2027 | £648.79 | £0.00 | £8,434.27 |
| Dec 2027 | £648.79 | £0.00 | £9,083.06 |
| Jan 2028 | £648.79 | £9,731.80 | £0.05 |
Annual tax, National Insurance, Capital Gains Tax and student loan estimate
| Component | Estimated amount |
|---|---|
| Income Tax | £7,486.00 |
| Class 4 NI | £2,245.80 |
| Total annual liability | £9,731.80 |
Compare the standard per-instalment estimate with the amount requested if you reduce it in the inputs.
| Instalment | Standard |
|---|---|
| First instalment (31 January 2027) | £0.00 |
| Second instalment (31 July 2027) | £0.00 |
| Component | Amount | Type |
|---|---|---|
| Income Tax | £7,486.00 | Tax |
| NI Class 4 | £2,245.80 | Tax |
| Balancing Payment | £9,731.80 | POA |
| Total | £9,731.80 | Total |
Model-informed prompts based on your tax-reserve estimate
Request email reminders for estimated future payment dates. Confirm deadlines against your HMRC account.
Copy the code below to embed the Tax Reserve Assistant on your site. Free to use with attribution.
<iframe
src=""
width="100%"
height="800"
style="border: none; border-radius: 12px; box-shadow: 0 4px 24px rgba(0,0,0,0.08);"
title="Tax Reserve Assistant Calculator"
loading="lazy"
></iframe>Get matched with a qualified accountant who specialises in self-employed tax. Free initial consultation.
Estimate a cash reserve for the 2025/26 or 2026/27 Self Assessment bill, including balancing payments and any modelled Payments on Account. Compare future tax deadlines with your current reserve and monthly saving capacity.
Enter annual estimates for self-employment profit, employment and property income, savings interest, dividends and other included amounts. Personal pension input means gross eligible relief-at-source contributions; net-pay workplace contributions and salary sacrifice are outside this field. Scotland applies Scottish bands to non-savings income. VAT is separate from this Self Assessment target.
This tool is an estimate, not your HMRC liability or payment schedule. It cannot confirm tax-relief eligibility, Payments on Account eligibility, payment-plan approval, MTD status or penalties. Check the current HMRC calculation, statement and official guidance before paying or changing instalments.
These HMRC and GOV.UK resources support the Self Assessment deadlines, Payments on Account, MTD, penalties, interest and CGT explanations on this page.