Better to claim additional rate tax relief on self-assessment or by contacting HMRC direct?

[mahirst]

Hello folks,

I am looking for some advice on the above.

I have a substantial amount of AR tax relief to claim back from HMRC as I used the 3-year carry back rules to top up contributions to my SIPP.

My company doesn't normally produce P60s until late May, so it feels like I should really grab the money as quickly as possibly and invest/save, given current high interest rates, etc.

Any advice please? Thanks