After you start a new job, HMRC asks you to allow at least 35 days — roughly five weeks — before expecting your correct PAYE tax code, because that is how long it takes your new employer’s payroll data to reach HMRC and be matched against your records.1GOV.UK. Tax Codes: If You Think Your Tax Code Is Wrong So the honest answer to how long it takes to get a tax code from HMRC is: about five weeks in the standard new-job case, or around 15 working days when you’re asking HMRC to change a code you already have. In the meantime you’ll usually be put on an emergency code, and any excess tax is refunded automatically once the correct code lands.
How Long It Takes in Each Situation
Starting a brand new job is the slowest scenario. Your employer sends your details to HMRC through their payroll software, HMRC matches that against your National Insurance record and anything reported by your previous employer, and then a code is issued. The 35-day window covers all of that.1GOV.UK. Tax Codes: If You Think Your Tax Code Is Wrong Once the code has been issued, you should see it on your next or second monthly payslip, or by your third weekly payslip.
If you already have a code and something has changed — a new taxable benefit, a second job, a company car, private health cover — HMRC aims to update your code and notify both you and your employer within 15 working days. After that, the same payslip timing applies: next or following payslip if you’re paid monthly, by the third payslip if you’re paid weekly.1GOV.UK. Tax Codes: If You Think Your Tax Code Is Wrong
Paper coding notices posted to you add transit time on top. If you want to see the code the moment it’s issued, the online Personal Tax Account is faster than waiting for the letter.
What You’ll Be Paid On Until Your Code Arrives
Until HMRC has the full picture, your new employer will operate an emergency tax code. You can spot one by the suffix at the end: W1 for weekly pay, M1 for monthly pay, or X for irregular pay dates.2GOV.UK. Tax Codes – Emergency Tax Codes So a code like 1257L M1 gives you the standard Personal Allowance but calculates each pay period in isolation, without accounting for what you’ve already earned or paid in tax so far this year.
The practical effect is that you often overpay tax in the short term, because the code can’t take account of allowances or tax already paid at a previous employer. This corrects itself. Once HMRC issues your cumulative code, your employer’s payroll recalculates the year to date and refunds any excess through your next payslip. No separate claim is needed in most cases.2GOV.UK. Tax Codes – Emergency Tax Codes
What Makes It Take Longer
A few things push you beyond the standard five weeks.
No P45 Handed Over
Your P45 is the fastest route to a correct code. It shows your leaving date, pay and tax from 6 April to your last day, your previous tax code, and your National Insurance number.3GOV.UK. Your P45, P60 and P11D Form – P45 It also records whether student loan deductions were being made.4HM Revenue & Customs. P45 Details of Employee Leaving Work You keep Part 1a and give Parts 2 and 3 to your new employer, who can then apply the right code immediately rather than waiting on HMRC.
The Wrong Choice on the Starter Checklist
No P45? Your employer will ask you to fill in a Starter Checklist, which asks you to pick one of three statements about your position since 6 April.5GOV.UK. Starter Checklist if You’re Starting a New Job
- Statement A: this is your first job since 6 April and you haven’t received Jobseeker’s Allowance, Employment and Support Allowance, or Incapacity Benefit. You get the full Personal Allowance on a cumulative basis.
- Statement B: you’ve had another job since 6 April but don’t have a P45, or you’ve received one of those benefits. You get the Personal Allowance on a non-cumulative (week 1 / month 1) basis.
- Statement C: you have another job or a state, workplace, or private pension. You go on the BR code, taxing all income from the new job at the basic rate.
Picking the wrong statement is one of the most common reasons people stay on the wrong code. Statement A gives the best immediate result, but choosing it when you’ve already used your allowance elsewhere in the tax year produces an underpayment that HMRC will collect later.6HM Revenue and Customs. Starter Checklist
Your Employer Filing Payroll Late
Under Real Time Information reporting, employers must submit payroll data to HMRC on or before each payday. When they file late, HMRC can’t issue or update your code on schedule. HMRC applies escalating monthly penalties for repeat late filings.7GOV.UK. What Happens if You Do Not Report Payroll Information on Time If your code seems stuck weeks after you started, this is worth ruling out.
How to Check Where Your Code Is Right Now
The quickest way to see your current code is HMRC’s online service on GOV.UK. Sign in and you can check your tax code and Personal Allowance, see estimated income from all your jobs and pensions, view whether your code has recently changed, and tell HMRC about changes that affect it.8GOV.UK. Check Your Income Tax for the Current Year Reporting a change online — say, a new company car — triggers an automatic recalculation, which is faster than waiting for post.
You can also call HMRC’s Income Tax helpline. Have your National Insurance number and your employer’s PAYE reference to hand so the adviser can find your record quickly. Once HMRC processes a change, it issues a P2 coding notice explaining how the code was worked out,9GOV.UK. PAYE Manual – PAYE11030 – Coding: Codes: How They Are Used and Calculated: P2 Notice of Coding and your employer receives its own notification (a P6) through payroll software or PAYE Online.10GOV.UK. Understanding Your Employees’ Tax Codes – Changes During the Tax Year
One boundary to note: if Self Assessment is the only way you pay income tax, for example if you’re fully self-employed, you don’t have a PAYE code and the service won’t show one.8GOV.UK. Check Your Income Tax for the Current Year
What Happens On Your Payslip Once the Code Arrives
When the correct cumulative code is applied, your employer’s payroll recalculates what you should have paid across the tax year so far and adjusts your next payslip. If you overpaid on the emergency code, the refund comes back through your wages automatically. If the overpayment sits in a previous tax year, HMRC usually issues a P800 calculation after the year ends and you can claim online or wait for a cheque.
Underpayments work differently. If HMRC finds you owe less than £3,000 (or a higher threshold if your income is above £30,000), they typically collect it by adjusting next year’s code rather than asking for a lump sum. Slightly more tax comes out of each payslip until the balance is cleared, usually inside one tax year, spread longer if the amount is large. Deductions taken through your code generally can’t exceed 50% of your wages. If HMRC can’t collect through PAYE — because you’ve left employment or left the UK — they’ll contact you to arrange payment another way, and interest may apply if the debt is spread over time.
If five weeks have passed, your Personal Tax Account still doesn’t show an updated code, and no refund or correction has come through your payslip, that’s the point to contact HMRC or check with your employer’s payroll team about whether your details have actually been submitted.