The Bottom Line
- Start with <strong>Tax Code</strong>, <strong>NI</strong>, <strong>NHS Pension</strong>, then <strong>Hours/Enhancements</strong>—most errors sit there.
- If your code shows <strong>W1/M1</strong> (or you’re taxed heavily), assume <strong>emergency tax</strong> until proven otherwise.
- Audit payslip against rota: <strong>nights (37%)</strong>, <strong>weekends</strong>, and <strong>additional rostered hours</strong> are frequently missed.
Step 1: Find the four fields that drive your net pay
On ESR payroll, most doctors only need four lines to sanity-check pay: (1) Tax code, (2) NI category + NI deducted, (3) NHS Pension contribution, (4) your enhancements (nights/weekends/additional hours). If any one is wrong, net pay can swing by hundreds.
Tax code 1257L in plain English
For most employees in England/Wales/NI, 1257L means you’re getting the standard Personal Allowance (typically £12,570) through PAYE. If you have multiple jobs, benefits-in-kind, prior underpaid tax, or started mid-year, the code can change. Use your tax code as your “headline”: wrong code = wrong deductions.
Emergency tax: the giveaway is W1/M1
If your payslip shows <strong>1257L W1</strong> or <strong>1257L M1</strong> (or an obvious spike in tax), you may be on an emergency basis—HMRC is taxing you “as if” this is the first week/month, often over-deducting until your record stabilises.
Income tax & NI: the numbers you should recognise
As a quick mental model for England/Wales/NI: income tax typically steps through 20% (basic), 40% (higher), 45% (additional). Employee Class 1 NI is commonly 8% between £12,570 and £50,270, then 2% above that (thresholds can change by tax year, but these are the figures most new IMGs will see first).
NHS Pension: why the % looks “high”
NHS Pension contributions are tiered by pensionable pay (not your take-home). Common tiers include 9.8% and 10.7% for many resident doctors; higher earners can be 12.5%. The key is: the pension line is usually one of the largest deductions, and it’s often correct even when it feels painful.
Enhancements that are often missing
Under the resident doctor contract, payslips often include items such as <strong>additional rostered hours</strong>, <strong>night duty (37%)</strong>, and <strong>weekend allowance</strong>. If your rota includes nights/weekends and those lines are absent, investigate immediately.
Payslip Audit Checklist (10 minutes, zero fluff)
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1) Confirm your tax code
If it’s not what you expect (e.g., 1257L), check your HMRC Personal Tax Account/HMRC app and ensure your employer details are correct.
2
2) Check emergency markers
Look for W1/M1. If present and you’re over-taxed, update HMRC employment details; emergency basis often corrects after HMRC syncs records.
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3) Verify gross basics
Your basic monthly pay should be roughly 1/12 of annual basic (adjusted for LTFT). If it’s off, payroll may have the wrong nodal point or LTFT fraction.
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4) Reconcile rota vs enhancements
Count nights/weekends worked in the pay period. Expect corresponding lines (night duty/weekend allowance). Missing lines = underpayment risk.
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5) Review NI & pension deductions
NI usually tracks income bands; pension is tiered. Big unexpected swings usually mean wrong assignment, backdated corrections, or a tier change.
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6) Escalate correctly
Email payroll with: assignment number, pay period, screenshot of rota segment, and a 3-line summary of the discrepancy. Keep it factual.
Practice
Test your knowledge
Apply this concept immediately with a high-yield question block from the iatroX Q-Bank.
SourceGOV.UK: Tax codes (what 1257L means)
Open Link SourceGOV.UK: Income Tax rates and Personal Allowance
Open Link SourceBMA: Understanding your payslip (resident doctors, 2016 contract)
Open Link