D1 Tax Code Meaning
The D1 tax code means all your income is taxed at 45% additional rate. Learn when it applies and how it impacts your pay.
What Does D1 Mean?
D1 stands for 'Additional Rate' and means all your income from this source is taxed at 45% with no Personal Allowance. This is the highest UK Income Tax rate, used when HMRC knows your total income exceeds £125,140.
How D1 Tax Code Works
With a D1 tax code, your employer deducts 45% Income Tax from every pound you earn, plus National Insurance contributions at 2%. This code is used for very high earners with multiple income sources, where additional income is taxed at the top rate.
How D1 Affects Your Take-Home Pay
Example: £30,000 (second job, main job earns £140,000)
- Personal Allowance: £0 (eliminated as income over £125,140)
- Taxable income: £30,000
- Income Tax (45% on all earnings): £30,000 × 45% = £13,500
- National Insurance (2%): £30,000 × 2% = £600
- Total deductions: £14,100
Take-home pay: £15,900 per year (£1,325 per month)
When is D1 Tax Code Used?
- •Your total annual income exceeds £125,140
- •You have multiple high-earning income sources
- •Your main employment already exhausts your Personal Allowance
- •You're a higher-rate taxpayer with additional pensions or directorships
How to Check Your Tax Code
You can find your current tax code in several places:
- •Payslip: Look at the top of your monthly payslip
- •HMRC online: Sign in to your personal tax account at gov.uk
- •P60: Your end-of-year certificate from your employer
- •PAYE Coding Notice: Letter from HMRC when your code changes
Calculate Your Take-Home Pay
See exactly how D1 affects your salary with our free calculator