HMRC Starter Checklist: Which Tax Code You Get

If you start a new job without a P45 from your previous employer, your new employer cannot use HMRC’s usual method of carrying your tax code across. Instead, you fill in the HMRC Starter Checklist — a short form (the old P46 is no longer issued) that asks a handful of questions and gets you to tick one of three statements: A, B, or C. Whichever one you pick decides the tax code your first payslip runs on, and getting it wrong is one of the most common causes of an unexpectedly small — or unexpectedly large — first pay packet.

This guide decodes exactly what each statement means, which code it produces, and what happens if you don’t fill the form in at all. To check what your actual code is doing to your pay, use the Tax Code Checker.

What the starter checklist is and when you fill it in

The starter checklist is for your new employer, not for HMRC — you never send it in. HMRC’s guidance says employers use it “to gather information about your new employee if they do not have a P45,” and employees are told to “give the completed form to your employer as soon as possible” because “they need this information to tell HMRC about you and help them to use the right tax code.”

You’ll typically fill one in if you:

• Are starting your first job since 6 April, or your first-ever UK job
• Don’t have a P45 because it hasn’t arrived yet, was lost, or your previous employer is slow
• Are returning to work after a break (education, unemployment, time abroad)
• Are starting a job alongside another job or a pension
• Have a student or postgraduate loan — the form covers this even if you do have a P45

If your employer has already run their first payroll submission for you (their first Full Payment Submission) before you hand over a late P45, they carry on with whatever code they’ve already used until HMRC sends a new one — the P45 doesn’t retroactively override an FPS that’s already gone in.

Statements A, B and C — decoded

The checklist boils your circumstances down to three mutually exclusive statements. Officially:

HMRC’s own employer guidance spells the mapping out in one line each: “Statement A – use the current personal allowance. Statement B – use the current personal allowance on a ‘week 1/month 1’ basis. Statement C – use tax code BR.” There is no branch of the checklist that produces 0T directly — 0T only appears if the checklist itself never gets completed (see below).

The form actually gets you there with three yes/no questions before you ever see the statements:

1. Do you have another job? Yes → Statement C.
2. Do you receive a State, workplace or private pension? Yes → Statement C.
3. Since 6 April, have you had another job that’s ended, or received Jobseeker’s Allowance, Employment and Support Allowance, or Incapacity Benefit? Yes → Statement B. No → Statement A.

So Statement A is really “clean slate, no other income this tax year”; Statement B is “I had income earlier in the tax year but not right now”; Statement C is “I have other income right now.”

Why Statement B means non-cumulative W1/M1

A normal tax code like 1257L works cumulatively: each payday, your employer looks at your total pay and tax so far this tax year and works out what you should have paid in total, then collects (or refunds) the difference. That’s what smooths out lumpy months automatically.

Statement B breaks that. HMRC has no visibility into what you earned or paid tax on at the job or benefit you had earlier in the year, so it can’t safely calculate a running year-to-date total. Instead your new employer applies the Week 1/Month 1 (“non-cumulative”) basis — each pay period is taxed in isolation, as if it were the only 1/52 or 1/12 of the year you’ll ever receive. You still get your full personal allowance sliced up proportionately, but none of it carries over, and nothing from earlier in the year is reconciled.

The practical effect: if you had a gap between jobs, or your previous job paid you less than a full year’s worth of income, a W1/M1 code usually overpays tax for as long as it stays on — sometimes for weeks. It self-corrects once HMRC has enough information to move you onto a cumulative code, and the overpayment is refunded automatically through payroll at that point. See emergency tax codes explained for how W1/M1 compares with the other emergency variants.

No P45 and no checklist — the 0T fallback

If you don’t hand over a P45 and you don’t complete the starter checklist before your first payday, your employer has no basis for A, B, or C at all. HMRC’s own tool for employers working out a new starter’s code covers exactly this case: when you’re unable to get a declaration from your employee, use tax code 0T on a ‘Week 1/month 1’ basis (and, for HMRC’s payroll reporting, record starter declaration “C” even though the actual tax code is 0T, not BR).

0T gives you no personal allowance at all, but — unlike BR — it still applies the normal 20% / 40% / 45% bands as your pay rises rather than a flat rate. Combined with the Week 1/Month 1 basis, this is the most aggressive default HMRC has: for a basic-rate earner it behaves almost identically to BR, but it can bite harder once pay crosses into higher-rate territory within a single pay period. The fix is simple — hand in your P45 as soon as it arrives, or ask your employer for the starter checklist and fill it in; there’s no reason to stay on 0T once either exists.

Student loan and postgraduate loan questions

The checklist also asks whether you have a student or postgraduate loan — you fill this section in even if you have a P45, because a P45 doesn’t always carry the plan type reliably. If you say yes, it walks through:

• Whether you’re still studying, finished your course after this tax year started, have already repaid in full, or pay the Student Loans Company by Direct Debit — any of those means no deduction is needed and you skip to the declaration.
• Otherwise, which plan applies: Plan 1, Plan 2, Plan 4, Plan 5, or a Postgraduate Loan. HMRC’s guidance is you tick only the one undergraduate-type plan you’re actually repaying, but you can tick a postgraduate loan on top of whichever plan applies, since the two deduct in parallel.

Employer guidance is explicit that if more than one plan type somehow gets flagged, they start deductions on whichever plan has the lowest repayment threshold and keep going until HMRC issues a formal Start Notice correcting it. Getting the plan wrong on the checklist means the wrong 9% (or 6% postgraduate) threshold gets applied from day one — use the Student Loan Calculator to check your plan and the deduction it should produce at your salary.

How the code gets corrected — and how refunds flow through payroll

Once your new employer’s payroll submission (or your late P45) reaches HMRC, HMRC cross-checks your record and, where needed, issues a corrected tax code — typically within 35 days of your start date, per HMRC’s own guidance on emergency codes. Two things happen next:

• If the new code is cumulative (dropping the W1/M1 or 0T basis), your very next payslip recalculates tax on your total year-to-date pay under the new code in one go — which automatically nets off any earlier overpayment as a larger take-home that pay period, no separate claim needed.
• If the tax year has already ended before the mismatch is caught, HMRC reconciles it after 5 April and sends either a P800 tax calculation or a Simple Assessment letter showing what’s owed or due back.

Check your code as soon as your first payslip lands with the Tax Code Checker, model the £ impact of a W1/M1 or 0T code with the Emergency Tax Calculator, and once you’re on the right code, confirm your expected net pay with the Take-Home Pay Calculator.

Frequently Asked Questions

Do I have to fill in a starter checklist if I have a P45?

Not for the tax code itself — your P45 already carries that. But you should still fill in the student loan section of the checklist if you have a student or postgraduate loan, since a P45 doesn’t always reliably show the plan type.

Which statement do I pick if I’m not sure whether I had other income since 6 April?

Answer the checklist’s own yes/no questions in order rather than guessing at A/B/C directly — they walk you through the exact criteria (another current job or pension → C; another job that’s ended, or JSA/ESA/Incapacity Benefit, since 6 April → B; neither → A).

Can I fill in the checklist late, after my first payday?

Yes — there’s no deadline that locks you out. Handing it in late (or handing in a delayed P45) still gets you moved onto a cumulative code and refunds any overpayment through your next payslip; it just means one or more pay periods ran on the more conservative 0T or W1/M1 basis first.

Is Statement B the same as an emergency tax code?

Effectively yes for how it behaves — non-cumulative, one pay period at a time — but it’s still built from your full personal allowance, unlike BR or 0T which strip the allowance away entirely. See Emergency Tax Codes Explained: BR, 0T, D0, D1 and W1/M1 for how the variants differ.

What if I tick the wrong statement by mistake?

Tell your employer as soon as you realise — they can correct the code on payroll going forward. If tax has already been over- or under-collected, it reconciles the same way as any other code correction: automatically in-year through a cumulative payslip, or via P800/Simple Assessment after the tax year ends.

Related tools and guides

• Tax Code Checker — decode any code, including the one your first payslip shows
• Emergency Tax Calculator — see the £ cost of a W1/M1 or 0T code and the refund due once it corrects
• Student Loan Calculator — confirm your plan and expected deduction
• Take-Home Pay Calculator — full PAYE + NI + student loan net pay once your code is right
• Tax Codes Explained 2026-27 — the full anatomy of every UK tax code
• Starting a New Job in the UK — P45, NI continuity and pension auto-enrolment alongside the checklist

Sources

• GOV.UK — Starter checklist for PAYE
• GOV.UK — Starter checklist (PDF form, HMRC 12/25)
• GOV.UK — Work out your new employee’s tax code
• GOV.UK — Tax codes: what your tax code means
• GOV.UK — Emergency tax codes
• GOV.UK — Tax overpayments and underpayments