The 1200L tax code means HMRC has set your tax-free Personal Allowance at £12,000 for the year. That is £570 lower than the standard allowance of £12,570 (code 1257L), so your employer is taking slightly more income tax from each payslip than someone on the default code. The reduction almost always reflects a taxable benefit from your job, a small amount of unpaid tax being collected through your code, or an out-of-date record at HMRC.
What the Number and Letter Actually Mean
Every PAYE code has two parts. The number, multiplied by ten, is the amount of income you can earn tax-free in the tax year. So 1200 means £12,000. The letter L confirms you get the standard Personal Allowance rather than a restricted or transferred version of it.1GOV.UK. Tax Codes – What Your Tax Code Means
The standard Personal Allowance for 2025/26 and 2026/27 is £12,570, which produces the code 1257L.2GOV.UK. Income Tax Rates and Personal Allowances That figure has been frozen since April 2021 and is set to stay put until at least April 2031.3GOV.UK. Income Tax – Maintaining the Personal Allowance Until 2031 If your code is 1200L instead, something has reduced your allowance by roughly £570, and it is worth knowing what.
Why Your Allowance Has Been Reduced by £570
HMRC lowers the number in your code whenever it needs to collect tax on something outside your regular wages, or to recover tax you owe from another source. For a 1200L code the reduction is modest, which points to a handful of likely causes.
- A taxable benefit from your employer. Company cars, private medical insurance, and other perks reported on a P11D each have a cash value that HMRC subtracts from your allowance. Medical cover worth around £570 a year, for example, is enough to move the code from 1257 to 1200.4GOV.UK. Tax on Company Benefits – Tax on Company Cars
- Unpaid tax from a previous year. Rather than sending you a bill, HMRC often spreads a small underpayment across the current year by trimming your code.5GOV.UK. What Will Happen If You Do Not Pay Your Tax Bill
- Untaxed income HMRC already knows about. Modest amounts of savings interest, rental income, or tips can be collected through PAYE instead of through Self Assessment.
- An error. A benefit you no longer receive, a second job you have left, or a stale data entry can all produce a code that no longer matches your situation.
HMRC issues a PAYE Coding Notice, often called a P2, whenever your code changes. It lists every addition and deduction that fed into the final number. If you never received one, the same breakdown appears in your Personal Tax Account online.
What 1200L Costs You Compared to 1257L
Your employer spreads the £12,000 evenly across the year. On monthly pay, the first £1,000 each month is tax-free; on weekly pay, about £230. Anything above that is taxed at the rate matching your income band.2GOV.UK. Income Tax Rates and Personal Allowances
For 2025/26 in England, Wales, and Northern Ireland, the basic rate is 20% on taxable income up to £50,270, the higher rate is 40% up to £125,140, and the additional rate is 45% above that. Compared with a 1257L code, a basic-rate taxpayer on 1200L pays an extra £114 a year in income tax (£570 × 20%). A higher-rate taxpayer pays an extra £228. The gap is small enough that most people never spot it on a single payslip, which is exactly why it goes unchecked.
Scotland sets its own rates and bands, but the arithmetic of the Personal Allowance is the same. A Scottish taxpayer on this allowance would see S1200L on the payslip; Welsh taxpayers see a C prefix.6GOV.UK. Income Tax in Scotland – Current Rates
How to Check Whether 1200L Is Correct for You
Start with your most recent payslip. The code usually sits near your National Insurance number or gross pay. If it reads 1200L and you do not receive any taxable benefits and do not believe you owe HMRC anything, the code is probably out of date.
Pull together the paperwork that shows what HMRC has been told about you:
- Your P60, which your employer issues after 5 April each year and which summarises pay and tax for the finished year.7GOV.UK. Your P45, P60 and P11D Form
- Your P45, given to you when you leave a job and used by the next employer to set your code.7GOV.UK. Your P45, P60 and P11D Form
- Your P11D, which lists the taxable benefits your employer has reported for you.7GOV.UK. Your P45, P60 and P11D Form
- The PAYE Coding Notice (P2), which shows exactly how HMRC arrived at 1200.
Compare the deductions listed in the coding notice against what is actually true today. A benefit you gave up, a second job that ended, or an old underpayment already cleared are all reasons the code may need to come back up.
How to Get the Code Changed
The quickest route is the Check Your Income Tax service on GOV.UK. Signing in with Government Gateway shows how HMRC built your code and lets you report changes to your income, benefits, or expenses directly.8GOV.UK. Check Your Income Tax for the Current Year The same job can be done through your Personal Tax Account.9GOV.UK. Personal Tax Account – Sign In or Set Up
If you would rather speak to someone, the HMRC Income Tax helpline is 0300 200 3300. Have your National Insurance number ready and be prepared to explain what has changed. Once HMRC updates the code, the new one is sent to your employer electronically and the corrected deductions appear on your next payslip.
Getting Back Tax You Overpaid
If you spent part of the year on the wrong code, HMRC usually catches the overpayment after the tax year ends and sends a P800 or Simple Assessment letter setting out what you are owed.10GOV.UK. Tax Overpayments and Underpayments You can claim online or wait for a cheque.
When the code is corrected partway through the year, PAYE tends to sort itself out on its own. Standard codes work on a cumulative basis, so your employer recalculates the year-to-date tax as soon as the new code arrives. That often produces one payslip with noticeably higher take-home pay as the overpaid tax is returned in a single go. If the year ends without a P800 and you still believe you overpaid, contact HMRC and ask for a review.