Cryptocurrency Gains of past tax years and Communication channels

Hullo, Crypto was my first foray into investing and i knew nothing of taxation... i only touched it because my mother was hospitalised during the height of covid...and i wanted to make some money (yes...stupid me...i know). I stumbled upon a youtube video summarising recent changes to crypto reporting regulations, in particular urging people to voluntarily report their as of yet undisclosed crypto income/gains taxes from past tax years with the HMRC claiming that 2025 will be the year that the government will hammer down and make some examples out of late payers.[link removed] I have amended my Self-assessment file for the [2022/2023] tax year using Koinly's tax reports and am told to wait 72 hours before any updates may be visible online. Also, I am in the process of declaring unpaid crypto taxes for the tax year [2021/2022] which is on a separate HMRC website (https://www.gov.uk/guidance/tell-hmrc-about-unpaid-tax-on-cryptoassets) So here are some issues i was wondering about : a)Can I use the CGT-allowance left over in that tax year to reduce my "Crypto Gains Tax Due" ?(e.g.CGT-tax-allowance of 12300 minus 2500 profits from stock sales = 9800 left over i can use to shield a part of my crypto gains?) b)Can I use what ever is left over from my personal allowance of 12570 to reduce my "Crypto Income Tax Due"? c)HMRC requires one to provide one document that shows calculations which should cover : Tax due,interest,penalties.The website also provides a spreadsheet seemingly for this purpose BUT the spreadsheet itself notes that "This calculator is for illustrative purposes only - it is not designed to formally determine tax and interest due." ...So what should one do here? Currently i am making an own Excel spreadsheet that follows the format of the HMRC calculator spreadsheet but i note that certain figures come from Koinly (e.g. Capital Gains Tax Due = 20%*Koinly-reported-gains)....Is this okay? How detailed should it be? When it comes to Interest payments...can i simply state the overall result coming from the HMRC calculator....without explictily showing the interim numbers...? d) Finally...i am not in the UK...i have no idea what if any letters are in my letterbox...i understand that about 30 days after submission of this declaration of an "offered amount" including a self-determined penalty + reason for failing to declare in time....the HMRC will send a letter to my address and either accept/reject my offer...But.. i am not in the UK! Can one manage this stuff online/over the phone ? Thank you

...why has my post been edited and clumped together like this?!

Reformatting my question a little so it is more readable :-) I am in the process of declaring unpaid crypto taxes for the tax year [2021/2022] which is on a separate HMRC website (https://www.gov.uk/guidance/tell-hmrc-about-unpaid-tax-on-cryptoassets) So here are some issues i was wondering about : a)Can I use the CGT-allowance left over in that tax year to reduce my "Crypto Gains Tax Due" ?(e.g.CGT-tax-allowance of 12300 minus 2500 profits from stock sales = 9800 left over i can use to shield a part of my crypto gains?) b)Can I use what ever is left over from my personal allowance of 12570 to reduce my "Crypto Income Tax Due"? c)HMRC requires one to provide one document that shows calculations which should cover : Tax due,interest,penalties.The website also provides a spreadsheet seemingly for this purpose BUT the spreadsheet itself notes that "This calculator is for illustrative purposes only - it is not designed to formally determine tax and interest due." ...So what should one do here? Currently i am making an own Excel spreadsheet that follows the format of the HMRC calculator spreadsheet but i note that certain figures come from Koinly (e.g. Capital Gains Tax Due = 20%*Koinly-reported-gains)....Is this okay? How detailed should it be? When it comes to Interest payments...can i simply state the overall result coming from the HMRC calculator....without explictily showing the interim numbers...? d) Finally...i am not in the UK...i have no idea what if any letters are in my letterbox...i understand that about 30 days after submission of this declaration of an "offered amount" including a self-determined penalty + reason for failing to declare in time....the HMRC will send a letter to my address and either accept/reject my offer...But.. i am not in the UK! Can one manage this stuff online/over the phone ? Thank you

Hi,
Capital gains tax is a separate tax to income tax and do not mix in any way.  
Any unused annual exempt allowance (AEA) can be set against other gains arising in the same tax year.  
The unused AEA cannot be carried forward or back or set against income tax.  
Unused personal allowanced cannot be set against capital gains tax.  
There is no spreadsheets or other type of file to support your evidence.  
It is up to you how to record the evidence, with the spreadsheet merely being nothing more than an example.  Create your own version.  
You can contact our self assesment helpline on +441619319070 from outside the UK (this overseas number will not work if you are in the UK) or contact our webchat facility at:
Contact HMRC
Monday to Friday 8am to 6pm Closed on weekends and bank holidays.
Thank you.

I appreciate your reply. Thank you, Good to know I can still use the AEA to offset Capital Gains and the personal allowance to offset Income for previous tax years. I have opted for email over letters when it comes to communication. Can I assume that when I submit the amendments,there will be no physical letters in response and all communication will be via email? I am asking since I am not in the country right now and the letter box must be full. Thanks.

Hi,
a) Yes.
 b)No. (Capital gains and income tax are two separate taxed and do not intermix)
c) It is up to you how you show this.  The example is there as a guide.  
It is up to you if you want to create a spreadsheet that matches the example or use a different design layout.  
You can contact HMRC from overseas at +441619319070 or via webchat:
Contact HMRC
Thank you.

Excuse me , you keep on saying "Capital gains and income tax are two separate taxed and do not intermix"...i am not sure where i gave the impression that this would be the case? I just wanted to confirm that : a)when calculating capital gains tax due : I can use AEA to offset Capital Gains & b)when calculating income tax due : the personal allowance can be used to absorb a portion of the income earned. I am not mixing anything here....or am I misunderstanding something? Thank you in any case.

Hi hip007,
HMRC does not use email for personal tax correspondence, as the medium is considered insecure.
For that reason, our correspondence is always by post.
Thank you. 

Hi HMRC Admin 25, Is this true even after changing the preferences on the Government Gateway website to email communication rather than post? ...Since i am not in the country right now...how would i receive the letters should there be any ? Is there a way to communicate by email instead ? Or by phone ? This query is related specifically to https://www.gov.uk/guidance/tell-hmrc-about-unpaid-tax-on-cryptoassets Thx

Hi hip007,
Any unused personal allowances cannot be transferred to Capital Gain Tax, they can only be ulitised against income.
For capital gains you have an annual exempt allowance.
Thank you. 

Hi hip007

Letters would still be issued by post as it is only automated items that would be done by email. You cannot correspond directly using email. You can use webchat to contact us if that is easier - Ask HMRC online

So...what do I do if HMRC send me a letter and I am out of the country? Can I provide another address ? Can one arrange another means of communication? How about sending tax letters through the Gateway-portal instead? This is the relevant website i am interested in : https://www.gov.uk/guidance/tell-hmrc-about-unpaid-tax-on-cryptoassets Thx.

Hi hip007,
You can nominate an address to have correspondence sent to that can be opened on your behalf.
You need to do this in writing and send it to:
MRC PAYE & Self Assessment BX9 1AS.
Thank you. 

But...there is nobody to nominate...! In the Gateway options i can specify a main address and a correspondence address...could i tell HMRC to send letters overseas for the duration i am out of the UK?

Hi hip007

Yes and then once you return to the UK, amend it back to your UK address.

Thank you

The advice given by the Admin in this post do not appear to be correct. I bit the bullet and submitted a voluntary disclosure form and this is the response i received: -------------------------------------------------------------------------------------------------------------- What happens next Within 15 working days, we’ll send you a payment reference number and details of how to pay. It will be sent by email if you consented to email communications. Otherwise it will be sent by second class post. If you have not received your payment reference number by 7 May 2024 contact us on 03000 552294. You need to pay by 9 May 2024. If payment is late, interest is added on a daily basis. We will then review your disclosure. If we accept it, we’ll send you a letter of acceptance. If we cannot accept it, we will contact you. From the HMRC Cryptoasset Disclosure team -------------------------------------------------------------------------------------------------------------- ...Amazing...so they can send letters by email after all? Or is it just the payment reference and not the "letter of acceptance" mentioned towards the end there?...Also...i have to pay BEFORE they review my disclosure?!...Am i understanding this correctly? How about...reviewing things BEFORE asking for payment ? Topsy Turvy.