What is a cumulative tax code? How is tax calculated if I am on a cumulative code with an income of 45k?

If you're put on a cumulative emergency tax code

You'll usually be put on a 'cumulative' emergency tax code if you've ticked Statement A on your P46 - telling your employer that this is your first job since the start of the tax year and you haven't been receiving any taxable pensions or state benefits.

How a cumulative emergency tax code might affect your wages;

The code used in this way will give you your full tax-free Personal Allowance over the remainder of the tax year - that's because your employer can carry forward any tax-free allowance not used in the period before you started your job. (As you've only just started work HMRC assumes that you haven't yet used any of your tax-free Personal Allowance.)

Your tax should be about right at the end of the tax year.

I hope this helps?

For further information doa Google serch on 'Cumulative Tax Code' and this will take you to the HMRC site.

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