Income tax Dates
Tax codes help your employer (or whoever pays you) work out how much tax to deduct from your pay, benefit or pension. Tax rates are used to work out how much tax you need to pay on your total income for the year, from all sources.
You need to choose a tax code for each source of income and provide this to your employer or income payer.
If your income changes, you may need to change your tax code, so you’re taxed correctly for each income source.