A 110L tax code means HMRC has reduced your annual tax-free personal allowance to £1,100, which is £11,470 below the standard £12,570 that most employees get under the 1257L code. The letter L confirms you still qualify for the standard personal allowance category; the number tells your employer how much of it you actually get. HMRC assigns this code when something in your circumstances requires a much smaller tax-free threshold, usually high earnings, taxable employee benefits, untaxed income, or tax owed from a previous year.
What the Number and Letter Mean
Multiply the number by ten to get your annual tax-free amount. So 110 × 10 = £1,100 you can earn each year before income tax applies.1GOV.UK. Understanding Your Employees Tax Codes – What the Numbers Mean The L simply signals the standard allowance category, even though the amount itself has been cut.2GOV.UK. Understanding Your Employees Tax Codes – What the Letters Mean
You’ll see 110L on your payslips and on your P60 at the end of the tax year. The document that actually explains it, though, is the P2 coding notice HMRC sends you directly. The P2 lists every addition and deduction that produced your final allowance figure, so if you want to know why your code looks the way it does, that’s the first thing to read.
Why HMRC Has Given You a 110L Code
Several separate situations produce an allowance of exactly £1,100, and the most common one has nothing to do with an error.
Your Income Has Crossed £100,000
Once your adjusted net income goes above £100,000, your personal allowance shrinks by £1 for every £2 you earn over that line.3GOV.UK. Income Tax Rates and Personal Allowances To lose £11,470 of allowance and end up on 110L, your income needs to be around £122,940. At £125,140 the allowance is gone entirely and HMRC switches you to a 0T code.
This is the single most common reason for a 110L code, and it often catches people off guard because nothing obviously changed. A bonus, share vesting, or a run of freelance work simply tipped your total income over the threshold, and HMRC adjusted the code automatically.
Taxable Benefits From Your Employer
Perks such as a company car or employer-paid private medical insurance are treated as taxable income.4GOV.UK. Other Company Benefits You Will Pay Tax On Rather than bill you separately, HMRC subtracts the cash value of those benefits from your allowance so tax is collected through PAYE. If your benefits are large enough, the allowance can drop all the way to £1,100. A fully electric company car carries a benefit-in-kind rate of 4% for 2026–27, but petrol or diesel vehicles can attract rates above 30%, which on a £40,000 car produces thousands of pounds of taxable benefit.
Untaxed Savings or Investment Income
Interest above your Personal Savings Allowance is taxable, but banks don’t deduct tax at source. HMRC’s fix is to reduce your code so the extra tax comes out of your wages or pension instead.5GOV.UK. Tax Codes – Why Your Tax Code Might Change Rental income and untaxed dividends above the dividend allowance are handled the same way. Large cash balances earning interest can produce a substantial adjustment on their own.
Underpaid Tax From an Earlier Year
If you underpaid tax by up to £3,000 in a previous year, HMRC recovers it by shrinking your current code across the year.6GOV.UK. PAYE12070 – Coding: Codes: How They Are Used and Calculated It’s gentler than a lump-sum demand, but combined with any of the factors above it can bring your allowance right down. Underpayments over £3,000 can’t be collected this way and go through Self Assessment or direct payment instead.
Several Smaller Adjustments Stacked Together
Often no single item is responsible. A modest company car, a few hundred pounds of untaxed interest, and a small prior-year underpayment can add up to the same £11,470 reduction. Your P2 lists each deduction separately, so you can see whether one large item or several smaller ones are driving the code.
How 110L Affects Your Take-Home Pay
The lost £11,470 of tax-free income costs you extra tax at your marginal rate. For 2026–27, the basic rate is 20% on taxable income up to £50,270, the higher rate 40% up to £125,140, and the additional rate 45% above that.7UK Parliament. Direct Taxes – Rates and Allowances for 2026-27
- At the basic rate: £11,470 × 20% = about £2,294 in extra annual tax, roughly £191 a month.
- At the higher rate: £11,470 × 40% = about £4,588 in extra annual tax, roughly £382 a month.
If you’re on 110L because of the £100,000 taper, you’re almost certainly paying at 40%, on top of income tax and employee National Insurance at 8% for 2026–27.7UK Parliament. Direct Taxes – Rates and Allowances for 2026-27 The combined squeeze is why a new 110L code so often prompts a call to payroll.
Cumulative Versus Month 1
Your employer applies the code on one of two bases. The cumulative basis is the default and works on a rolling year-to-date total, so if HMRC switches your code from 1257L to 110L mid-year, your next payslip or two may take a large deduction to catch up on tax that should have been paid earlier.8GOV.UK. PAYE11090 – Coding: Codes: How They Are Used and Calculated: Ways an Employer Can Apply a Tax Code
Month 1 (or Week 1) basis treats each pay period on its own and ignores the year to date. HMRC uses it when it doesn’t want a large single-period swing. You’ll see M1 or W1 next to the code. The trade-off is that you can end the year slightly over- or under-taxed, which HMRC reconciles afterwards.
Scottish Taxpayers
If you live in Scotland, your code will read S110L. Scotland sets its own rates: a 19% starter rate, then 20%, 21%, 42%, 45%, and a 48% top rate on income above £125,140 for 2026–27.9Scottish Government. Scottish Income Tax 2026 to 2027 – Technical Factsheet The personal allowance and the £100,000 taper work identically, but the monthly hit from losing allowance can differ because the applicable band rate differs.
How to Check and Correct the Code
The quickest route is HMRC’s online “Check your Income Tax” service or the HMRC app, which shows your current code, the calculation behind it, and lets you update income, benefits, or other details.10GOV.UK. Check Your Income Tax for the Current Year Once HMRC accepts a change, it issues a P6 notice to your employer with the new code.11GOV.UK. Understanding Your Employees Tax Codes – Changes
A few things worth knowing:
- If you’ve just started a new job, HMRC advises waiting 35 days before querying the code, because your new employer’s records need time to feed through.
- Read the P2 first. The error, if there is one, is usually a benefit you no longer receive or an income estimate that’s out of date.
- If the online service can’t handle your issue, you can call HMRC, though wait times can be long.
When the Allowance Would Drop Below Zero
If deductions for benefits and adjustments exceed your entire personal allowance, HMRC doesn’t stop at zero. You get a K code instead, which adds the excess to your taxable income.12GOV.UK. Tax Codes – If You Have a K in Your Tax Code Where 110L shelters £1,100, a K396 code adds £3,960 to your taxable pay. Your employer can never deduct more than half your pre-tax pay through a K code, whatever the figure. If your P2 shows deductions nearly wiping out your allowance, one more benefit or prior-year underpayment could tip you into K code territory.
If You’ve Been Overtaxed
When HMRC corrects a code mid-year, any refund normally comes back through your pay. Your employer applies the new code and returns the excess tax on your next payslip, or within a few pay periods for weekly pay.13GOV.UK. Tax Codes – If You Have Paid Too Much or Too Little Tax You don’t file a claim separately.
If the overpayment relates to a previous tax year, HMRC reconciles after the year ends using data from your employer, then writes to you with the refund amount and method. If you file Self Assessment, the adjustment goes through your return. Every month you leave a wrong code in place is another month of reduced take-home pay you didn’t need to accept, so correcting the code promptly is the fastest way to get the money back.