Tax relief is a top up on your pension payments from HMRC. It broadly works by giving you back some of the tax you’ve paid on your salary. This amount of tax relief is based on the basic rate of income tax (20%), which means you'll get a free £20 for every £80 you add to your pension account.
You don’t need to do anything to receive basic tax relief – Dodl will claim it on your behalf and pay it directly into your pension. However, if you're a higher-rate or additional-rate taxpayer, meaning you’re entitled to extra tax relief on top, you'll have to apply for it through your self-assessment tax return.