The total amount of tax you pay shouldn’t change, no matter how many PAYE jobs you hold. The amount of tax you pay at each job might be different, though. Here’s why.
Income Tax
You can only apply your £12,500 tax-free personal allowance to one job.
You only get one personal allowance, so it’s usually best to apply it to your highest-paying job.
If you earn over the personal allowance in a second job during the year, your total effective rate of tax will be exactly the same. It might seem like one job is more heavily taxed, but this will be because you’re using your personal allowance in your primary job.
National Insurance
You will only pay National Insurance on earnings above £166 per week in any job.
A note about pension contributions
You’ll receive pension contributions from both jobs if you meet the auto-enrolment conditions.
You can opt out of pension schemes, but it’s not recommended as this offers both a tax saving and employer's contribution of 3% of eligible earnings.
If you’re ever taxed more than you should have been, some of your money could come through as an automatic refund from HMRC. You might also have to claim some of it back yourself via a tax rebate. Read more about this here, on Money Advice Service.
To learn more, we recommend seeking professional advice about tax and pensions based on your unique circumstances.