Welsh Rates of Income Tax (WRIT) for teachers — the 'C' code guide

Decoding the 'C' on your Welsh payslip

If you live and teach in Wales, a quick look at your monthly payslip will reveal a distinct modifier on your tax code: the letter 'C' prefix (for example, C1257L).

This prefix indicates to your school's payroll software or local authority clearing house that you are classified as a Welsh Taxpayer by HMRC, making your earnings subject directly to the Welsh Rates of Income Tax (WRIT) framework administered by the Senedd.

How the Welsh income tax split operates

The Welsh Government holds devolved statutory control to modify the basic, higher, and additional rate percentages for individuals residing in Wales.

Mechanically, HMRC reduces the standard UK Income Tax rate by 10p across all bands for Welsh residents, and the Senedd then votes on the exact percentage to add back on. For the active 2026/27 fiscal cycle, the Senedd has locked the rates to match the rest of the UK exactly:

• Welsh basic rate: 20% (10% UK + 10% Welsh Rate) on taxable income up to £50,270.
• Welsh higher rate: 40% (30% UK + 10% Welsh Rate) on earnings between £50,270 and £125,140.
• Welsh additional rate: 45% (35% UK + 10% Welsh Rate) on all earnings exceeding £125,140.

While the net tax percentages currently align perfectly with England and Northern Ireland, tracking this split is vital because your overall tax liability is heavily shaped by how your regional tax code interacts with your pension plan.

The interaction between WRIT and the Teachers' Pension Scheme (TPS)

Because the Teachers' Pension Scheme (TPS) utilises a Net Pay Arrangement, your progressive pension deductions (ranging from 7.4% to 12% based on your actual gross salary) are subtracted from your pay packet before the Welsh Rate of Income Tax is calculated.

Let's look at the mathematical flow for a Welsh teacher on the U1 Upper Pay Scale point (£50,236):

1. Gross annual salary: £50,236.00
2. TPS pension deduction (9.9% tier): £4,973.36
3. Taxable income remaining for WRIT: £45,262.64
4. Apply Welsh Personal Allowance (C1257L): deduct £12,570.00
5. Total income assessed at 20% Welsh basic tax: £32,692.64

The fiscal-drag shield

Notice what happens at the higher boundary: because your base salary of £50,236 sits right on the edge of the 40% Higher Rate threshold (£50,270), a standard worker would be dangerously close to stepping into the higher tax bracket.

However, because your £4,973.36 pension contribution is removed from your taxable gross up front, your final taxable earnings drop to £45,262.64. This leaves you with a protective buffer of £5,007.36 before a single penny of your salary can be taxed at the 40% Welsh Higher Rate.