Control 1
Eligibility evidence
Age, apprenticeship status, payment date and retained apprenticeship evidence.
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UK National Insurance correction guide
Employee on the wrong NI category H: how to correct previous payroll years
Verify category H eligibility, separate current-year from prior-year FPS corrections and reconcile every affected outcome without recreating NICs manually.
UK employersReviewed July 2026Based on HMRC correction guidance
Correction boundary
Category H is for eligible apprentices under 25—not a general lower-rate category.
Establish the evidence and affected payment dates before selecting a corrected category or reporting route. Do not alter old payroll evidence to make a new category appear to have applied all along.
Local-only correction guide
What is the correct starting route?
Check the facts, then submit the route. This guide does not calculate NICs, prepare an FPS or decide the legal recovery of an employee deduction.
What does the category H eligibility evidence show?
Five-domain correction map
One category letter can affect several controlled outcomes.
Control 2
Payroll record
Original and corrected category letter, pay periods and year-to-date data.
Control 3
Employee NIC
Repayment or recovery analysis, authority and communication.
Control 4
Employer NIC and HMRC
Liability movement, additional FPS and account reconciliation.
Control 5
Audit trail
Original reports, correction decision, responses and preventive control.
Current year and previous years
Use the maintained route for the affected tax year.
Current tax year
Correct through the next FPS using the relevant category and year-to-date data.
6 April 2020–5 April 2026
Use an additional FPS with the correct category and correct year-to-date NIC for the relevant year.
Do not recreate NIC manually
Use maintained payroll software and source data; do not turn a historic correction into a spreadsheet-rate exercise.
The case must preserve original records, correct employee NIC where needed and reconcile the employer liability. It does not end when the category letter is changed in a profile.
Browse all NI correction routes
This static route browser is available without JavaScript. It is not a determination of eligibility, NIC values or a real reporting outcome.
Keep the evidence and check what triggered the review
The available evidence supports category H for every affected payment. On these facts, the category-H review does not itself identify a correction to submit.
Start with: Retain the eligibility evidence with the employee record.
Verify category H eligibility before changing payroll
The available evidence does not yet establish whether category H was valid for every affected payment. Category H is for eligible apprentices under 25, not a general lower-rate category.
Start with: Check date of birth, apprenticeship status, payment dates and the evidence required for the apprenticeship arrangement.
Use the current-year category-letter correction route
The incorrect H category affects only the current tax year. HMRC’s maintained route is through the next FPS with the incorrect and correct category information and corrected year-to-date NIC figures.
Start with: Recalculate through maintained payroll software; do not recreate statutory NIC calculations manually.
Split and correct each affected prior tax year
The error includes one or more tax years from 6 April 2020 to 5 April 2026. HMRC says to send an additional FPS with the correct category letter and correct year-to-date NIC figures for each affected year.
Start with: Make a correction case for each tax year; do not merge different years into one unsupported adjustment.
Separate employee NIC adjustment from the reporting correction
The category error caused an employee National Insurance overpayment or underpayment. HMRC requires the employee deduction position to be corrected as well as the category reporting.
Start with: Establish the employee NIC difference through maintained payroll software.
Pause and establish the correction facts before reporting
Eligibility, affected years or the employee NIC position is unclear. An incorrect category should not be replaced by a guessed category or an unsupported manual submission.
Start with: Preserve the employee record, apprenticeship evidence, payroll outputs and existing RTI history.
Verify category H before changing payroll
Category H is for eligible apprentices under 25. It is not a general lower-rate category. Confirm the employee’s date of birth, apprenticeship status, payment dates and the evidence required for the apprenticeship arrangement before deciding that the letter was wrong for any period. GOV.UK category letters and the HMRC employer guide set out the category and evidence context.
Do not backdate the employee’s master record to make an earlier category appear correct. Preserve the original payroll and RTI evidence, then create a correction case for the periods that are actually affected.
Split current-year and prior-year reporting
For a wrong category letter in the current tax year, HMRC says to report the correction through the next FPS using the relevant incorrect and correct category data and correct year-to-date NIC figures.
For mistakes in tax years from 6 April 2020 to 5 April 2026, HMRC says to send an additional FPS with the correct category letter and correct year-to-date National Insurance for that category. Treat each tax year as its own controlled correction rather than merging several years into one unsupported adjustment. HMRC’s FPS and EPS correction guidance
Keep the correction outcomes separate
A wrong category can affect several things at once:
- employee National Insurance deductions;
- employer National Insurance liability;
- the employee payroll record;
- FPS reporting and HMRC’s account; and
- any employee communication, repayment or recovery.
The gross correction, employee NIC movement and employer liability are not automatically the same amount. Use maintained payroll software to establish the supplied values; this guide does not calculate National Insurance.
Employee NIC overpayments and underpayments
HMRC says employee National Insurance deductions must be corrected where the wrong category created an overpayment or underpayment. Before recovering anything from a later payment, establish lawful authority, timing and applicable restrictions. Do not assume that an alleged employee balance permits a deduction from wages. GOV.UK: correcting pay or deductions
Keep any employee repayment or recovery separately evidenced from the FPS correction and from the employer’s liability reconciliation.
Reconcile and retain the case record
For each affected tax year, retain:
- evidence of the category-H eligibility review;
- original and corrected payroll outputs;
- employee NIC and employer NIC differences as separate values;
- additional or next-FPS references and HMRC responses;
- HMRC account reconciliation; and
- the route decision, reviewer and preventive action.
HMRC says a penalty for a payroll mistake depends on whether the employer failed to take reasonable care or acted deliberately; it is not an automatic consequence of every error. Correcting promptly and retaining the evidence is still important. HMRC correction guidance
Related resources
- Lesson 11: Handle changes, leavers and corrections
- Lesson 10: Send EPS, reconcile and pay HMRC
- Understand deductions and net pay
Sources and review
Reviewed July 2026 by the Workmax payroll team. This guide is educational only. It does not decide an employee’s apprentice status, calculate NICs, authorise a deduction or confirm that an HMRC correction is complete.
Complete the correction chain
A correct FPS is only one outcome in the case.
Use Lesson 11 for correction controls and Lesson 10 to reconcile employer liabilities and HMRC account movements after reporting.
