UK CGT Same Day Pooling (HMRC)

Hi Guys,

According to the UK HMRC crypto assets manual (see: CRYPTO22200 - Cryptoassets Manual - HMRC internal manual - GOV.UK) the “Same day rule” says tokens (either acquired or disposed of on the same day) should be treated as “single” transaction(s) and would require 1 calculation only to work out the gain/loss.

Have attached some images of some test transactions that I added manually to Koinly. The way Koinly has worked out the cost basis does not seem to match the HMRC rules… unless I have missed something obvious, could you please explain this discrepancy?

This is “rule 1” of the HMRC asset matching CGT rules… so if this is not 100% correct on your system then my confidence in Koinly is severely reduced.

Please advise on this possible issue… as the cost basis should be £150, with a £150 profit.

Note: My settings are for the UK and Shared Pool / Individuals.


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Can some one from Koinly support please respond to this as if the calculation is incorrect it has quite serious implications to all your UK users?


Hi guys,

Thanks for reporting this. Same day transactions were being handled using FIFO but have now been updated so that they are treated as a single transaction as per the updated examples on HMRC’s website. This should only affect people that bought/sold the same asset on the same day at very different prices (like in your example) and did not sell all of those assets in the following 30 days.

You will now see a $0 value on most deposits on the same day and a higher value on the first deposit (since all deposits are pooled into a single txn). We are rolling the change out gradually and you will receive an email from us if your gains are affected. You can also apply the new changes to your account manually by changing your cost basis method from Share Pooling [Legacy] to Share Pooling / Individuals.



Thanks for getting the Koinly team to fix this. As you mentioned above it made very little difference to the calculation as although I have done a fair bit of buying and selling the same day the price wasn’t dramatically different within that one day.

Hi Petur,

Thanks very much for looking into this and updating the system to handle same day pooling.