Tax Code 1256L Explained

1256L means you have £12,560 of tax-free income – £10 less than the standard £12,570. HMRC has deducted a small amount, usually to collect tax on a small taxable benefit, some untaxed income, or a small amount of tax you owe. The L means you're still on the standard allowance.

Tax-free allowance implied by this code: £12,560 a year (£1,046.67 a month).

How your pay is taxed on 1256L

Example (England, £30,000, 1256L): (£30,000 − £12,560) × 20% = £3,488 a year, about £290.67 a month – roughly 17p a month (£2 a year) more than 1257L. Small code reductions like this have a small effect on tax.

Tax-free allowance from this code£12,560Cumulative

Income tax with this code	£3,488
Income tax with standard 1257L	£3,486
Difference per month	£0.17

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Why you might have this code

A small taxable benefit or untaxed income (e.g. a little savings interest above your allowance) is being collected.
A small underpayment from a previous year is being collected – HMRC divides the tax owed by your tax rate to get the code reduction.
HMRC rounded an adjustment to the code number.

What to do

Check the code HMRC holds for you in your personal tax account (GOV.UK sign-in) or the HMRC app – it also shows how the number was worked out.
Compare it with the code on your latest payslip. If they differ, ask payroll whether they have applied HMRC’s latest notice.
Look at the deductions listed by HMRC. If an item is wrong or out of date, ask HMRC to remove it.

See all tax codes or check your take-home with the UK salary calculator.

How small is the adjustment behind 1256L?

Very small. HMRC rounds deductions down to the pound and then drops the last digit of your net allowances. 1256L therefore covers net allowances of £12,560 to £12,569, meaning HMRC is taking off between £1 and £10. That costs £0.20 to £2 a year at 20%, or up to £4 at 40%.

Three things that commonly produce it

Savings interest just over your Personal Savings Allowance. A basic-rate taxpayer gets £1,000 of interest tax-free. If HMRC estimates £1,010, the £10 excess is deducted from your allowance, giving 1256L.
A tiny underpayment from last year. HMRC converts tax owed into a code reduction by dividing by your tax rate: £2 owed at 20% is a £10 reduction.
A small taxable item reported by your employer or included in HMRC’s estimate of your income.

Why a 1256L change doesn’t come with emergency tax

When HMRC lowers a code during the year, it checks how much extra tax is due up to the date of the change. Its PAYE Manual says that if the amount is under £15, the new code stays cumulative. That’s why a move from 1257L to 1256L normally appears without any M1 marker. A larger reduction often does come with one.

Should you bother challenging it?

Only if the item is wrong. The tax effect is small, but a wrong interest estimate tends to be repeated: HMRC’s manual lets staff use the same figure for the next year unless they know it will be different. If you’ve moved savings into an ISA or interest rates have fallen, update the estimate in your personal tax account so the deduction doesn’t carry on.

In Scotland, S1256L costs up to £1.90 a year at the starter rate. In Wales, C1256L costs the same as in England.

Code boundaries near 1257L

HMRC rounds deductions down to whole pounds, then the last digit of the allowance is dropped. A deduction of £19.60 counts as £19, giving 1255L. These are the bands around the standard code:

Total deductions	Code
£0	1257L
£1 to £10	1256L
£11 to £20	1255L
£21 to £30	1254L

Finding the item behind 1256L

Sign in to your personal tax account or the HMRC app and open the tax code breakdown for this job or pension.
Look under deductions. Typical labels are interest, benefits, underpayment and other earnings.
For interest, compare HMRC’s figure with your bank’s annual interest statements. If you’ve moved money into an ISA, that interest doesn’t count.
If the item is right, leave it – the cost is a few pence a month. If it’s wrong, change the estimate online. A cumulative code then refunds the small overpayment on your next payday.

Why 1256L often appears in April

Many small deductions arrive at annual coding. HMRC’s manual says the system assumes this year’s coding items continue into next year unless staff know otherwise, and that an interest figure can be carried forward unless a better estimate is known. So a small interest estimate, or a benefit your employer reported for the first time, can turn 1257L into 1256L from 6 April without anything changing in your pay.

The same manual tells staff to cover items such as interest, small fees and tips, property income and State Pension by deducting them from the allowances at your main (primary) source – which is why the deduction appears in your main job or pension’s code.

Frequently asked questions

Is 1256L the same as 1257L?

Almost: £10 less allowance, costing about £2 a year at 20%.

Why did my code change to 1256L?

HMRC has an adjustment to make – check the breakdown in your personal tax account or the HMRC app.

Is 1256L an emergency code?

No.

Should I challenge 1256L?

Only if the deduction is wrong. If HMRC is collecting tax genuinely owed, the code is correct.

Does 1256L affect my National Insurance?

No. Tax codes only affect Income Tax. National Insurance is worked out on your pay in the normal way.

How much more tax will 1256L cost me?

Between £0.20 and £2 a year at the basic rate – a few pence a month.

Is my savings interest estimate based on last year?

Usually. HMRC can carry the current year’s figure forward unless it knows the amount will be different, so update it if your savings have changed.

Is 1256L an S or C code too?

It can be. S1256L and C1256L carry the same £1 to £10 deduction, with tax at Scottish or Welsh rates.

Why not 1257L if the deduction is under £10?

Because the code number is the allowance with its last digit dropped. Any deduction from £1 to £10 takes the allowance below £12,570, into the 1256 range.

Can I just pay the tax instead of having 1256L?

If the deduction is collecting an underpayment, you can pay HMRC directly before the new tax year starts. For an ongoing item like interest, the code is the normal way to collect it.

Will 1256L go back to 1257L?

If it’s collecting a one-off underpayment, yes – usually from the next 6 April. If it’s for an ongoing item like savings interest, it stays until HMRC’s estimate changes.

Could 1256L be connected to Marriage Allowance?

No. Marriage Allowance changes the letter as well as the number – 1383M for the partner receiving it and 1131N for the partner giving it. 1256L is a standard L code with a small deduction.

Sources

Figures are taken from official government publications and were last reviewed on 2026-10-03.