What does the GOV.UK tax checker actually do?

The GOV.UK "Estimate your Income Tax for the current year" service estimates your take-home pay for the 6 April 2026 to 5 April 2027 tax year, covering Income Tax, National Insurance, pension contributions and student loan repayments, from figures you type in. It is published by HMRC — the authority whose rules every other tool, including PayslipIQ, works from. It is a forward-looking estimator: it does not read a payslip or tell you whether a specific deduction your employer made was applied correctly.

Why would I use PayslipIQ when HMRC has an official checker?

Because the two do different jobs. The HMRC estimator models what your pay should look like from typed inputs. PayslipIQ starts from the payslip itself: upload a photo or PDF and each line — tax code, NI, pension, student loan — is extracted and checked against the published rules, with a per-line verdict. When something is flagged, HMRC is exactly where we point you next: your Personal Tax Account and, if needed, an HMRC adviser.

Can everyone use the GOV.UK estimator?

No. HMRC states it is not for the self-employed (who are directed to the Self Assessment calculator) or for people whose only income is state benefits, and that people with more than one job should run it once per job. PayslipIQ checks whatever PAYE payslip you upload, but it is an educational tool — for a definitive answer on your tax position, HMRC remains the authority.

Which figures should I trust if the two tools disagree?

HMRC's. PayslipIQ works from HMRC's published 2026/27 thresholds and shows its methodology precisely so you can check our arithmetic against the official source. If a PayslipIQ verdict and an HMRC figure ever disagree, treat HMRC as correct and tell us — a discrepancy on our side is a bug we want to fix.

Educational guidance only — not regulated tax, financial or payroll advice. This page is an independent comparison written by PayslipIQ; it is not endorsed by, affiliated with or produced in cooperation with HMRC or GOV.UK. On any question of tax law or your personal tax position, HMRC is the authority.

UK · Comparisons · GOV.UK tax checker

PayslipIQ vs the GOV.UK tax checker — an honest comparison

The GOV.UK “Estimate your Income Tax” service is published by HMRC — the body that writes the rules every other tax tool merely models. This is not a comparison between rivals: PayslipIQ defers to HMRC on the underlying numbers. What this page explains is the one thing the official estimator is not designed to do — read the payslip your employer actually gave you — and where each tool fits as a result.

Run the PayslipIQ payslip check

The short answer

The GOV.UK estimator answers “what should my take-home be this year?” with the full weight of HMRC behind the arithmetic — Income Tax, National Insurance, pension and student loan, for the 2026/27 year. PayslipIQ answers a narrower, later question: “does the payslip I was just handed match those rules?”. Model with GOV.UK; audit the document with PayslipIQ; and if anything is genuinely wrong, resolve it through your HMRC Personal Tax Account or payroll team.

Where the GOV.UK checker wins

Several of these are not merely strengths — they are things no third-party tool can offer at all.

It is the authority. HMRC sets the thresholds, rates and rules. When the estimator and any third-party tool disagree, the estimator is right by definition. PayslipIQ’s own maths is checked against HMRC’s published figures.
It connects to your real tax record. The estimator sits inside the GOV.UK estate alongside your Personal Tax Account and the HMRC app, which show your actual tax code, coding notices and payment history. No independent tool has that data, and none should.
Full component coverage in one official place. Income Tax, National Insurance, pension contributions and student loan repayments in a single free public service, with clear signposting to Self Assessment where it applies.
It is where problems actually get fixed. A wrong tax code is corrected through HMRC, not through any checker. Whatever tool spots the issue, GOV.UK is the road to the remedy.

What PayslipIQ adds

“Adds” is the honest word — these are gaps in scope, not flaws in the official service.

It reads the actual document. The estimator never sees your payslip; you transcribe figures into it. PayslipIQ extracts them from the photo or PDF directly, which is faster and removes transcription errors.
A per-line verdict rather than a single estimate. Tax code, NI, pension and student loan lines each get an expected-vs-observed comparison, so you know which line to query rather than just that the total looks odd.
Coverage of messier payslip types. Umbrella-company and agency-worker payslips have dedicated checkers that look for patterns — missing employer NI lines, opaque margins — that a salary estimator was never meant to address.

Side-by-side comparison

The differences are of scope and role, not quality.

Feature	GOV.UK estimator	PayslipIQ
Who publishes it	HMRC. The rules every other tool models are set here — this is the authoritative source, full stop.	An independent educational tool that works from HMRC’s published 2026/27 rules and shows its methodology.
What question it answers	“What should my take-home be this tax year?” — a forward-looking estimate from typed figures.	“Is the payslip I was actually given correct?” — a backward-looking check of a real document.
Components covered	Income Tax, National Insurance, pension contributions and student loan repayments for 6 April 2026 to 5 April 2027.	The same four components, checked line by line against what appears on the uploaded payslip.
Reads your payslip	No. You type the figures in yourself.	Yes. Photo or PDF in; gross, tax code, NI, pension and student loan lines extracted and reconciled.
Who it excludes	Not for the self-employed (Self Assessment calculator instead) or people whose only income is state benefits; more than one job means one run per job.	Any PAYE payslip can be checked, including umbrella and agency slips. Self-employment income is out of scope for both.
Connection to your real tax record	The wider GOV.UK estate connects to it — your Personal Tax Account and the HMRC app show your actual tax code and payment history.	None. PayslipIQ sees only the payslip you upload, nothing from HMRC’s systems.
Privacy approach	Typed figures only on the open estimator; the signed-in services sit behind Government Gateway.	The payslip image is uploaded, processed for the check and not stored. No account, no signup.
Price	Free — a public service.	Free check, no signup. A £19 Pro Report is planned at launch (currently waitlist only).

Use GOV.UK when / use us when

You want this year’s official take-home estimate. Use GOV.UK. There is no better source for what the numbers should be.
You want to see your actual tax code or coding notice. Use your HMRC Personal Tax Account or the HMRC app — no third-party tool can show you these.
You are holding a payslip that looks wrong. Use PayslipIQ first. The per-line verdict tells you which deduction to query — then take that specific question to payroll or HMRC.
You are an umbrella or agency worker with an unusual slip. Use PayslipIQ’s dedicated checkers, then escalate anything serious to HMRC — disguised-remuneration schemes are exactly the sort of thing HMRC wants reported.

Frequently asked questions

What does the GOV.UK tax checker actually do?: The GOV.UK "Estimate your Income Tax for the current year" service estimates your take-home pay for the 6 April 2026 to 5 April 2027 tax year, covering Income Tax, National Insurance, pension contributions and student loan repayments, from figures you type in. It is published by HMRC — the authority whose rules every other tool, including PayslipIQ, works from. It is a forward-looking estimator: it does not read a payslip or tell you whether a specific deduction your employer made was applied correctly.
Why would I use PayslipIQ when HMRC has an official checker?: Because the two do different jobs. The HMRC estimator models what your pay should look like from typed inputs. PayslipIQ starts from the payslip itself: upload a photo or PDF and each line — tax code, NI, pension, student loan — is extracted and checked against the published rules, with a per-line verdict. When something is flagged, HMRC is exactly where we point you next: your Personal Tax Account and, if needed, an HMRC adviser.
Can everyone use the GOV.UK estimator?: No. HMRC states it is not for the self-employed (who are directed to the Self Assessment calculator) or for people whose only income is state benefits, and that people with more than one job should run it once per job. PayslipIQ checks whatever PAYE payslip you upload, but it is an educational tool — for a definitive answer on your tax position, HMRC remains the authority.
Which figures should I trust if the two tools disagree?: HMRC’s. PayslipIQ works from HMRC’s published 2026/27 thresholds and shows its methodology precisely so you can check our arithmetic against the official source. If a PayslipIQ verdict and an HMRC figure ever disagree, treat HMRC as correct and tell us — a discrepancy on our side is a bug we want to fix.

Free payslip check
Upload a photo or PDF — get a line-by-line verdict.
All comparisons
PayslipIQ vs the other UK tax tools, honestly compared.
Wrong tax code checker
Guided check for the most common “is my code right?” patterns.
Methodology, DPIA & sub-processors
How the parsing works, where data is processed, what is logged.

Last reviewed

Last reviewed: 4 August 2026

Next review: 6 April 2027

Reviewed each tax year and sooner if either tool changes materially.

Educational guidance only — not regulated tax, financial or payroll advice. Independent comparison; not endorsed by, or affiliated with, HMRC or GOV.UK. On your personal tax position, HMRC is always the authority.