Tax Code 1100L Explained
1100L gives a Personal Allowance of £11,000 (the number 1100 × £10). This is lower than the standard 1257L code, meaning you pay tax on a slightly larger portion of your income. You pay 20% basic rate on income between £11,001 and £50,270, then higher rates above that. The difference versus 1257L is £157 more tax per year.
What does tax code 1100L mean?
Tax code 1100L gives you a reduced Personal Allowance of £11,000 instead of the standard £12,570. You pay £314 more tax per year compared to 1257L. HMRC has reduced your allowance to collect tax on untaxed income or benefits.
Who gets tax code 1100L?
Employees whose tax code has been adjusted downward — for example, to collect tax on a small untaxed income source (such as rental income or a state pension element), a benefit in kind from their employer, or underpaid tax from a previous year being spread over the current year.
Take-home pay on tax code 1100L — 2025-26 examples
Examples below show Income Tax and take-home pay at common salary levels. National Insurance (NI) is also shown separately — NI is not affected by your tax code and applies on the same basis for all employees.
| Gross Salary | Income Tax | NI (est.) | Take-Home | Effective IT Rate |
|---|---|---|---|---|
| £20,000 | £1,800 | £594 | £17,606 | 9.0% |
| £25,000 | £2,800 | £994 | £21,206 | 11.2% |
| £30,000 | £3,800 | £1,394 | £24,806 | 12.7% |
| £35,000 | £4,800 | £1,794 | £28,406 | 13.7% |
| £40,000 | £5,800 | £2,194 | £32,006 | 14.5% |
| £45,000 | £6,800 | £2,594 | £35,606 | 15.1% |
| £50,000 | £8,060 | £2,994 | £38,946 | 16.1% |
| £60,000 | £12,060 | £3,211 | £44,729 | 20.1% |
| £75,000 | £18,060 | £3,511 | £53,429 | 24.1% |
| £100,000 | £28,060 | £4,011 | £67,929 | 28.1% |
Take-home = Gross − Income Tax − National Insurance. No pension, student loan or other deductions included. NI calculated at 8% between £12,570–£50,270 and 2% above. Effective IT Rate shows Income Tax as a percentage of gross salary.
Tax code 1100L vs 1257L: take-home comparison
How much more or less you take home on 1100L compared to the standard 1257L code at the same gross salary. A negative number means less take-home pay.
| Gross Salary | 1257L Take-Home | 1100L Take-Home | Difference |
|---|---|---|---|
| £20,000 | £17,920 | £17,606 | -£314 |
| £25,000 | £21,520 | £21,206 | -£314 |
| £30,000 | £25,120 | £24,806 | -£314 |
| £35,000 | £28,720 | £28,406 | -£314 |
| £40,000 | £32,320 | £32,006 | -£314 |
| £45,000 | £35,920 | £35,606 | -£314 |
| £50,000 | £39,520 | £38,946 | -£574 |
| £60,000 | £45,357 | £44,729 | -£628 |
| £75,000 | £54,057 | £53,429 | -£628 |
| £100,000 | £68,557 | £67,929 | -£628 |
Both columns include Income Tax and National Insurance. No pension or student loan deductions. 1257L = standard Personal Allowance of £12,570.
If you have tax code 1100L, here's what you should know
- Your tax code appears on your payslip, P60, and any correspondence from HMRC about your PAYE tax.
- Your employer uses this code to calculate how much Income Tax to deduct from each pay period — they do not set it themselves.
- If your circumstances change (new job, change in benefits, marriage allowance), your code should update automatically — but it is worth checking.
- You can view and update your tax code online via your Personal Tax Account at gov.uk.
- If you think your code is wrong, contact HMRC on 0300 200 3300 or use the HMRC app.
- An incorrect tax code can mean you overpay or underpay tax — overpayments are refunded, underpayments are collected in future years.
Frequently asked questions
What does tax code 1100L mean?
1100L gives a Personal Allowance of £11,000 (the number 1100 × £10). This is lower than the standard 1257L code, meaning you pay tax on a slightly larger portion of your income. You pay 20% basic rate on income between £11,001 and £50,270, then higher rates above that. The difference versus 1257L is £157 more tax per year.
Who gets tax code 1100L?
Employees whose tax code has been adjusted downward — for example, to collect tax on a small untaxed income source (such as rental income or a state pension element), a benefit in kind from their employer, or underpaid tax from a previous year being spread over the current year.
How much do I take home on tax code 1100L earning £30,000?
On tax code 1100L with a £30,000 salary, you take home £24,806 per year (£2,067 per month) after Income Tax of £3,800.
Is tax code 1100L correct for me?
Your tax code is set by HMRC based on your individual circumstances. If you believe your tax code is wrong, contact HMRC on 0300 200 3300 or check your Personal Tax Account at gov.uk. An incorrect code could mean you are paying too much or too little tax.
How do I change tax code 1100L?
To change tax code 1100L, contact HMRC directly on 0300 200 3300 or update your details via your Personal Tax Account at gov.uk. Your employer cannot change your tax code — only HMRC can issue a new one. Once HMRC updates your code, they will notify your employer and the change will appear on your next payslip.
Will I get a refund if tax code 1100L was applied in error?
If tax code 1100L was applied incorrectly and caused you to overpay Income Tax, HMRC will refund the overpayment. This typically happens automatically via a P800 tax calculation sent after the tax year ends (April). For a faster refund, contact HMRC directly once the correct code has been issued. Overpayments can also be reclaimed through Self Assessment if you file a return.
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