Why There Is an Extra Pay Day
The tax year runs from 6 April to 5 April: 365 days, or 366 when it contains 29 February. Fifty-two weeks is 364 days. The one or two days left over (5 April, or 4 and 5 April) form tax week 53.
An employer whose weekly pay day lands in week 53 pays 53 times in the year. For any one pay day of the week this happens about once every five or six years.
Which Payrolls Are Affected
| Pay frequency | Normal periods a year | Extra period is called | When it happens |
|---|---|---|---|
| Weekly | 52 | Week 53 | The pay day falls on 5 April (or 4 April in a year with 29 February) |
| Fortnightly | 26 | Week 54 | The 27th fortnightly pay day falls in week 53 |
| Four-weekly | 13 | Week 56 | The 14th four-weekly pay day falls in week 53 |
| Monthly | 12 | Never | Month 12 always ends on 5 April |
The coming years
| Tax year | Week 53 falls on |
|---|---|
| 2026/27 | Monday 5 April 2027 |
| 2027/28 | Tuesday 4 and Wednesday 5 April 2028 |
| 2028/29 | Thursday 5 April 2029 |
So a client who pays weekly on a Monday has a week 53 in 2026/27. Find the tax week of any date with the tax week and month calculator.
How the Extra Pay Day Is Taxed
The tax tables only run to week 52. By then a cumulative calculation has already given the employee their full year's tax-free allowance, so a 53rd cumulative calculation would have nothing left to give.
HMRC's rule is to tax the payment on a non-cumulative, week 1 basis:
- Give one further week's free pay (two weeks' for week 54, four weeks' for week 56)
- Apply one week's share of each tax band to this payment alone
- Ignore pay and tax to date for the calculation
The employee therefore receives slightly more tax-free pay over the year than their code allows: 53 weeks' worth where the code is worth 52. HMRC may collect the small difference later, usually through the following year's tax code.
Why it matters most for a final bonus
For an employee paid the same every week, the difference between the right and wrong method is pennies. For one whose week 53 payment includes a bonus or a large final payment it can be hundreds or thousands of pounds, because a cumulative calculation would spread the payment across the whole year's bands while the week 1 basis applies one week's bands to it.
National Insurance
Nothing special. National Insurance is not cumulative for ordinary employees, so week 53 is assessed against the normal weekly thresholds like any other week. Company directors on the annual method are unaffected, since their thresholds are annual.
What the FPS Shows
The Full Payment Submission reports the pay day as tax week 53, 54 or 56, and marks the tax as calculated on a week 1 basis for that payment. The employee's tax code itself does not change, and week 1 of the new tax year reverts to the normal basis.
Things to Check in March
- Does the client's pay day fall on 5 April? If the pay day is normally the 5th or later but pay is brought forward, there is no week 53: the tax week is set by the actual payment date.
- Is the client prepared for a 53rd week of wages? Salaried staff paid weekly may be contracted for an annual salary divided by 52. Whether a 53rd payment is due is a contract question, not a tax one.
- Pension contributions are due on the extra pay as usual.