Do tax codes affect how much NI is paid?

What_time_is_it

My partner’s tax code recently changed. She was on 1257 and,
since 1st April this year, she is now on 1300. Effectively she had a tax free allowance on £13,001 this year.

she got her payslip today and the tax she has paid this month has been calculated on the basis of £13,001 tax free, but the NI she has paid has been calculated using £12,570 tax free. 

Is this correct? Is NI always calculated this way?

Dazed_and_C0nfused

Yes, NI is totally different.

Gaberdeen

Tax codes make no difference to NI.

Tax codes adjust your tax-free allowance therefore determining what your overall taxable income is. Ni is calculated on your pre-tax income so is not affected by tax codes.

i.e. a Salary of £30,000 per year will attract NI of £1394.40 a year regardless of tax code or region of the UK (i.e. Scotland, England, Wales, Northern Ireland)

The only thing that can affect employee NI is net-pay arrangements such as salary sacrifice pension contributions or cycle to work schemes which reduce your salary ergo will reduce NI.

What_time_is_it

Thanks guys. I had always assumed that tax codes impacted both tax and NI, so that’s really good to know.