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IsMyPayRight

Corrections log

When a figure, rule or instruction on this site turns out to be wrong, we fix it and record it here. Newest first.

Spotted something? Email hello@ismypayright.co.uk with the page address and what you expected. See how to report a problem.

  1. Take-home pay above £100,000

    What was wrong
    Between £100,000 and £125,140, the reduced Personal Allowance kept fractions of a pound.
    What it does now
    The reduced allowance is now worked out in whole pounds, as the Income Tax Act 2007 (section 35) requires. Affected results changed by less than £1 a year.

  2. Maternity pay calculator

    What was wrong
    Where employment ended before maternity pay started, the calculator accepted a Statutory Maternity Pay start date that the rules do not allow.
    What it does now
    The calculator now shows the start date that applies for that employment end date and asks you to confirm it with payroll.

  3. D0 tax code guide

    What was wrong
    The guide said D0 “usually” means all pay is taxed at the higher rate, and described the effect loosely.
    What it does now
    It now states that D0 applies 40% to all taxable pay from that job or pension, with no Personal Allowance there, and links to HMRC’s PAYE manual.

  4. Tax code guidance for a new job

    What was wrong
    Guides told new starters without a P45 to complete a starter checklist at any point.
    What it does now
    The starter checklist is for details before your first payment. After you have been paid, update your details through HMRC’s Check your Income Tax service.

  5. Electric car salary sacrifice

    What was wrong
    Company car tax was estimated from the annual lease price.
    What it does now
    The calculator now asks for the car’s P11D value and works out the tax from the car benefit itself.

  6. Marriage Allowance

    What was wrong
    For the person receiving the transfer, the calculator raised their Personal Allowance, which gave the wrong answer at Scottish rates.
    What it does now
    It now applies a tax reduction, capped at £252 and at the tax actually due, as HMRC does.

  7. Two jobs calculator

    What was wrong
    The annual National Insurance maximum for two jobs was estimated from combined gross pay.
    What it does now
    It now follows HMRC’s method in the National Insurance Manual (NIM01272). HMRC’s published example of two £51,600 jobs gives the same £3,866.70 maximum.

  8. Day rates

    What was wrong
    Day rates were turned into a yearly salary using 365 days, so £300 a day showed as £109,500 a year.
    What it does now
    A year now has 260 working days, so £300 a day is £78,000 a year.

  9. Personal Allowance above £100,000

    What was wrong
    The allowance reduction ignored relief-at-source pension contributions. At £110,000 with a 10% contribution, tax was overstated by £2,000.
    What it does now
    The reduction now uses adjusted net income, which deducts the grossed-up pension contribution.

  10. Statutory Sick Pay from April 2026

    What was wrong
    The calculator still applied the lower earnings limit, so someone earning £5,000 a year was told they would get nothing.
    What it does now
    From 6 April 2026, SSP is the lower of the flat rate and 80% of average weekly earnings. On £5,000 a year that is £76.92 a week.

  11. Enhanced maternity pay

    What was wrong
    An enhanced scheme could show less than Statutory Maternity Pay for some weeks.
    What it does now
    Each week now pays the higher of the enhanced amount and Statutory Maternity Pay.

  12. BR and D0 codes on week 1 or month 1

    What was wrong
    Codes printed without a space, such as BRW1 or D0M1, were taxed through the normal bands. At £200,000, BRW1 showed £76,203 tax instead of £40,000.
    What it does now
    These codes now use the flat rate, however the code is written.