HMRC calculates your end-of-year tax estimate based on the information you provide. This includes:
Sage doesn’t calculate your tax. Instead, HMRC processes your submitted information to create the estimate.
Your Personal Allowance is one of the allowances HMRC applies. It's the amount you can earn before you pay Income Tax.
For detailed guidance, visit gov.uk/estimate-income-tax.
The accuracy of your tax estimate depends on the completeness and accuracy of the data you submit to HMRC.
Your estimate can be less accurate if you:
Your tax estimate doesn't require immediate payment. Actual tax becomes due only after you complete and submit your final declaration at the end of the tax year.
Remember, this estimate is a helpful planning tool and doesn’t represent your final tax bill.