How do I know letters have been processed?

Hi I sent a letter to HMRC in November 2021 - claiming allowable losses from 2017 to 2021 - as per https://www.gov.uk/capital-gains-tax/losses. The letter included details of losses from those years (some shares, some crypto), as well as referencing some I reported in my 2011/12 losses which had been reported through Self Assessment (which I no longer need to do), and reported what my total allowable losses were including those. In TY 2020/21 I made a little over 13000 gain - on the phone (Jan 2022) I was advised that I could simply write a letter to declare this and "use" some of those allowable losses, without having to fill in SA and be back in the system of annually filling in SA. So in January 2022 I sent another letter, stating my gains in 2020/21, the gain above the 12,300 allowance, and therefore the reduction in future allowable losses to carry for future years. They weren't "questions" so I wasn't necessarily expecting a reply, but as I haven't received any letter of acknowledgement, how would I know if these have actually been logged? Is there actually an "allowable losses" field in a database somewhere with my name on it, or is it just a paper trail? Should I have expected to receive any acknowledgement of these letters having been received and processed? Thanks For info letters were sent to Capital Gains Tax Queries HM Revenue and Customs BX9 1AS and included my UTR

Hi groucho123,
You would normally receive an acknowledgement.
With regards to the 20/21 year, as you made a gain over the annual exempt amount this should have been confirmed by submitting a tax return
and on the return you would show that you have used some of your losses to leave a balance to carry forward.
Thank you.

OK, so the fact I've sent 2 letters and received zero acknowledgement implies that HMRC have lost both...despite me having got Royal Mail confirmation of delivery at least for the first one...! It also seems from what you're saying that I was mis-inform by HRMC when they told me I could simply write a letter regarding my CGT as there was nothing actually to pay. I have a note of what date and time I made the telephone call where I was advised as such. How best to proceed - obviously I have done everything that I have been advised based on the HMRC website and subsequent telephone advice from the same. I have acted in good faith and of course want to ensure I am not subject to any penalties due to misguidance. My gains for 2021-22 and 2022-23 were under the annual allowance so there has been no more correspondence (though of course I have records) not Self Assessment submissions. Thanks

Hi groucho123,
The correspondance you've sent so far may still be being processed.
If you'd like us to review the progress of this correspondance, or give specific advice on your capital gains submissions and how they should be recorded, please contact us by webchat or post here:
Self Assessment: general enquiries 
Thank you.