Tax Code 1100L Explained

What does 1100L mean?

1100L was the default UK PAYE tax code for the 2016/17 tax year. Like today's 1257L it represents a standard personal allowance of £11,000 (number × 10) for taxpayers in England, Wales and Northern Ireland with no allowance adjustments. If you see 1100L on a current payslip it almost certainly indicates a stale code that should have been uplifted at the start of the new tax year - HMRC normally issues a P9 in March each year to refresh codes for April. Check your most recent P2 in your personal tax account; if it shows the current 1257L but your payslip still reads 1100L, the issue is on the payroll side and your employer needs to apply the latest P9. Historical codes are useful for reading old P60s or P45s but should not appear on a current payslip without explanation.

Breakdown of the code

• 1100

  Number

  Personal allowance for 2016/17: £11,000.

• L

  Letter

  Standard allowance, no special adjustments.

Worked example

Reading an old P60 from 2016/17 on £30,000 (paid monthly).

Useful only when reconciling pre-2016/17 earnings.

Who should be on 1100L?

• Reading a P60 or P45 from the 2016/17 tax year
• Historical reference only - never on a current payslip

Common problems

• Appears on a current payslip - payroll has not applied the latest P9 from HMRC.
• Used as the starting point for a fresh starter checklist when 1257L should have been used.

What to do if 1100L looks wrong

1. Sign in to your HMRC personal tax account at gov.uk/personal-tax-account and open the latest P2 (Notice of Coding) - it itemises every adjustment.
2. Compare the code on your most recent payslip with the code HMRC has on file; employers occasionally apply an old code if a P9 was missed.
3. Confirm your employer received your P45, or that you completed a starter checklist if you joined mid-year.
4. Check whether benefits-in-kind such as a company car, fuel, or medical insurance have changed and ask payroll to file an updated P11D.
5. Call HMRC on 0300 200 3300 (Mon-Fri, 8am-6pm) with your National Insurance number if the online tools cannot resolve it.
6. If you have overpaid, HMRC normally refunds via your next payslip once the code is corrected. For closed years request a P800 review.

If you should be on a different code…

Quick decision tree - when 1100L is the wrong fit, here is the most likely correct code.

• If you have a single PAYE job and no benefits-in-kind - you should be on 1257L.

  Standard personal allowance of £12,570 for England, Wales and NI.