Key takeaways
- April is the one month of the year when your payslip can change without your salary changing — a new tax year starts on 6 April, bringing a fresh set of codes, thresholds and rates.
- Your code should be 1257L unless you have a reason for something else — and April is when HMRC issues new ones.
- The minimum wage rises on 1 April, not 6 April — check your hourly rate against your age band.
- If any of the seven checks fails, do not wait for it to fix itself — April errors compound monthly.
April is the one month of the year when your payslip can change without your salary changing. Seven checks, ten minutes, and you will catch every common April error.
DRAFT — not for publication until April 2027. Recurring annual format. Re-check every rate against GOV.UK at the April 2027 fiscal event before it goes live.
A new tax year starts on 6 April, and with it comes a fresh set of codes, thresholds and rates — and a fresh set of payroll errors. Most April mistakes are small, silent and cumulative: a wrong code that costs you £50 a month for a year before anyone notices. This checklist is the same every April, and it takes less time than reading the payslip properly once.
1. Your tax code
The single most important check. Your code should be 1257L unless you have a reason for something else — and April is when HMRC issues new ones. If it says BR, D0, 0T or anything with a K, find out why before you accept it: a wrong code in April is a wrong code all year. See our guide to 1257L and when your tax code is wrong, and check your Personal Tax Account, which shows the code HMRC actually holds.
2. Your personal allowance
Your payslip should show the monthly slice of your allowance — £12,570 a year is £1,048 a month. If you earn over £100,000, the taper applies: you lose £1 of allowance for every £2 above £100,000, and it is gone entirely at £125,140. April is when the taper first bites for people who crossed £100,000 during the year, and the payslip is the first place it shows.
3. The minimum wage uprating
The minimum wage rises on 1 April, not 6 April — and it is the one April change that is easy to miss on a salary. Check your hourly rate against your age band: the National Living Wage (21+) is £13 an hour, 18–20 is £11, 16–17 and apprentices £8. If your pay did not move on 1 April and you were close to the old rate, run the minimum wage checker — and count your real hours, unpaid overtime included.
4. National Insurance
Employee National Insurance is 8% of pay between £12,570 and £50,270 a year, then 2% above. On a monthly payslip that is 8% above £1,048 a month. If your April payslip shows NI on your whole salary, or NI at the wrong rate, something is wrong — the most common cause is a payroll system that has not picked up the new thresholds. Your employer's NI is not on your payslip, but the cost of employing you rose with it, so April is also when pay negotiations get harder.
5. Your student loan
Student loan thresholds are frozen for years at a time, which means they quietly bite harder as pay rises. Plan 2 is £29,385, Plan 1 £26,900, Plan 4 £33,795, Plan 5 £25,000, Postgraduate £21,000 — all at 9% (6% for Postgraduate) above the threshold. If your April pay rise took you over a threshold for the first time, the deduction starts this month, and the payslip is the first you will see of it. Check the plan is right, too: the wrong plan is a common payroll error, and it changes the deduction by hundreds of pounds a year.
6. Your pension
April is when pension percentages change, auto-enrolment bands move and salary sacrifice arrangements renew. Check the contribution on your payslip against what you agreed — 5% of qualifying earnings (£6,240–£50,270) is the auto-enrolment default, and your employer should be paying at least 3%. If you salary-sacrifice, check the sacrificed amount matches the agreement, and remember the April 2029 cap on the NI exemption is coming: from 6 April 2029 only the first £2,000 a year of employee pension salary sacrifice stays NIC-exempt. Nothing changes for 2027/28, but April is the right month to plan for it.
7. The new rates themselves
Finally, check the rates. The 2027/28 main rates are published unchanged — personal allowance £12,570, the same bands, the same NI — but savings and property rates rise to 24% / 44% / 49%, the trading allowance triples to £3,000, and the Lower Earnings Limit rises to £133 a week. The full preview is on UK tax rates 2027/28, and the live rates are on UK tax rates 2026/27. Run your salary through the take-home pay calculator once, compare it with your April payslip, and if they disagree by more than a few pounds, ask payroll — politely, with the numbers in hand.
The check most people skip: your pension
Of the seven checks above, the pension is the one most people never look at — and it is the one where the most money quietly goes missing. Auto-enrolment puts you in at 8% of qualifying earnings (5% from you, 3% from your employer), but qualifying earnings are not your whole salary: pension is calculated on earnings between £6,240 and £50,270, so on a £35,000 salary your pensionable pay is £28,760, not £35,000. If your payslip shows a pension deduction that does not match 5% of that band, something is off — either the band is wrong, the percentage is wrong, or you are on a different scheme with different rules. And if you opted out of the pension years ago, April is the month your employer must re-enrol you every three years: check that you are back in, or that you have opted out again deliberately, not by accident.
The other pension check is salary sacrifice. If your employer offers it, your pension contributions come out before tax and NI, which saves you 8% NI on the sacrificed amount — and saves your employer 15%. If your employer does not offer it, ask: it costs them nothing to set up and it saves them money on every employee who joins. One warning for 2026/27: there is no cap on the NI saving this year, but from 6 April 2029 only the first £2,000 a year of sacrificed pension contributions stays NI-exempt. That does not change anything you do this April, but it is worth knowing that the arrangement has a known expiry date on its full benefit — and if your employer is slow to set it up, the years of full saving are the years to use it.
What to do if something is wrong
If any of the seven checks fails, do not wait for it to fix itself — April errors compound monthly. A wrong tax code is fixed through HMRC, not your employer: check your Personal Tax Account first, because it shows the code HMRC actually holds, and if it is wrong there, HMRC can correct it and issue a new code to your employer within days. A minimum-wage shortfall goes to your employer in writing first — underpayment is often a missed April uprating — and if that does not work, ACAS offers free advice and HMRC investigates. A wrong student loan plan or a pension percentage that does not match your agreement goes to payroll, with the agreement or the Student Loans Company letter in hand. And if your payslip disagrees with the take-home pay calculator by more than a few pounds, take both to payroll: the calculator shows the right answer for a standard case, so a gap means something specific is different — a tax code, a pension mode, a salary-sacrifice arrangement — and finding it in April is worth a year of correct pay.
One last April habit: keep the April payslip. Not in a drawer — somewhere you can find it. It is the baseline for the whole year: the code, the thresholds, the pension, the loan. When something looks wrong in October, the April payslip is the document that shows when it changed. And if you ever need to prove your income — for a mortgage, a rental application, a benefits claim — the April payslip plus your P60 in May are the two documents that matter.
Ten minutes in April, once a year, is the cheapest financial admin there is.
Run your salary through the calculator
Run your salary through the take-home pay calculator once, compare it with your April payslip, and if they disagree by more than a few pounds, ask payroll — politely, with the numbers in hand.
DRAFT — figures from the 2026/27 rates and Budget 2026, last checked against GOV.UK on 5 November 2026. Re-check at the April 2027 fiscal event before publishing.