Describe the problem:
I sold some bitcoin in August 2025, submitted a tax report to HMRC, the P&L was ~ £15.4K
Ipaid what I owed - all good.
In Feb 26, I have bought approx £500 of bitcoin, and transferred this to my hardware wallet.
Each transaction showed a loss of less than £1.00
If i now run a tax report, it now says my profit for this year is £19K !!!
I don’t understand, surely it should be be £15.4K minus a few pounds.
If I look at the Capital Gains Transactions Report, I can see the same transactions as before, dates and amounts are the same but the gain & loss are different.
Eg:
In the report created in August 25, the first CGT transactions record is as follows…
Date Sold Date Acquired Asset Amount Cost (GBP) Proceeds (GBP) Gain / loss Notes Wallet Name
08/07/2025 17:40 BTC 0.03610423 1,720.12 2,915.74 1,195.62 Section 104 pool Tangem
It shows a Gain / loss of £1,195.62
If I run the report now, I get different figures…
Date Sold Date Acquired Asset Amount Cost (GBP) Proceeds (GBP) Gain / loss Notes Wallet Name
08/07/2025 17:40 BTC 0.03610423 1,374.64 2,915.74 1,541.10 Section 104 pool GSW_Tangem
It shows a Gain / loss of £1,541.10
How can the same transaction report on two different profits depending on when the transaction report is run?
Which exchange/wallet is this regarding?
Revolut, Coinbase & Tangem
How did you import data into this wallet?
SYNC automatically
What have you tried to fix this so far?
I don’t understand what has happened, how can the same transactions report different gains depending
on when the tax report is run?