Tax code decoder
The standard code: £12,570 of tax-free pay for 2026/27
What each part means
- The number 1257 means you get £12,570 to £12,579 of tax-free pay in the year, which is £1,048.25 a month or £241.90 a week. Multiply the number by 10 to get the rough annual amount.
- 1257L is the code most people have: the full Personal Allowance of £12,570 with nothing added and nothing taken away.
- The letter L means you are entitled to the standard Personal Allowance.
- The X at the end means the code is being used on a week 1 / month 1 basis: each payday is taxed on its own, ignoring what has happened earlier in the year. It is still a normal tax code. HMRC uses this basis when something changes part-way through the year: a benefit or other deduction goes in, expenses or another allowance are added or taken away, or pay goes above £100,000 and the Personal Allowance shrinks. Taxing each payday on its own stops the change being applied to the months already gone; any tax owed for those months is collected through an in-year adjustment in the code, or after the year ends.
Your tax-free pay under this code
Per year
£12,579
Per month
£1,048.25
Per week
£241.90
Everything you earn above this is taxed at the normal rates. On a cumulative code, unused allowance from earlier months carries forward.
Does it look right?
Right for most people with one job or pension and nothing else going on.
- If you have a second job or pension, that source should be on a different code (usually BR), not another 1257L, or you will get the allowance twice and owe tax later.
- If you receive a State Pension, have a company car or medical insurance, or get untaxed interest or rent, your code should normally be lower than this. If it is not, HMRC may not know, and a bill can follow.
- The week 1 / month 1 marker means each payday is taxed on its own. It usually follows a change part-way through the year: a benefit, an allowance, untaxed income or a pay rise over £100,000. The months before the change are not reworked, so check whether an in-year adjustment for them is in the code. If the marker is still there two or three months later, ask HMRC for a cumulative code.
If you think it is wrong
- 1
Sign in to your Personal Tax Account. Under PAYE you can see what HMRC thinks you earn from each source and what is in your code, and you can correct most of it yourself.
Personal Tax Account (GOV.UK) - 2
If you would rather talk to someone, ring the Income Tax helpline on 0300 200 3300 with your National Insurance number to hand. Ask them to explain each line of your code and to send you a P2 if you have not had one.
Income Tax enquiries (GOV.UK) - 3
Once HMRC changes your code they send the new one to your employer or pension provider. Any tax you overpaid earlier in the year comes back automatically in your next pay on a cumulative code.