Once you have a small emergency fund you should make sure you are enrolled in your employer’s automatic enrolment pension scheme. This is a minimum of 3% extra pay in exchange for you contributing 5% of your take-home pay.

What if I’m self-employed or not eligible to join the pension scheme?

If you’re employed but haven’t been automatically enrolled, it means you’re either too young or don’t earn enough. You’re almost certainly still eligible to join, but will have to opt-in. Speak to your employer.

If you’re self-employed you will need to arrange your own pension scheme. This is a higher priority than it would be otherwise.

More information within the Wiki here:

and further down the same page here: