Not sure if there are enough UK users to make it worthwhile for Koinly to implement any of these suggested improvements so your service complies with the UK HMRC guidance on Crypto taxes.

The one area your service does not comply with is the HMRC guidance is implementing the section on allowable expenses correctly (link below and first attached image is of relevant section)

The part Koinly does not implement correctly is deducting the transfer fees from the capital gains.

To achieve this several small improvements would be required.

1) A new tag of transfer fee would need to be created (currently if I move a coin such as FIL to a hardware wallet you pay an ETH gas fee to have it included on the block chain. Currently this is listed as a Cost in Koinly. If this could be tagged as a Transfer fee it means on the full report under expenses, it would be included in the Transfer fees Total instead of the Cost Total).

2) For UK users add an extra option in the settings section “Deduct Transfer fees from capital gains” so we could turn it on or off (this would add the transfer fee total to Acquisition costs, subtract it from profits before losses and subtract it from Net gains) you would also need to change/add a remark in full report to state that transfer fees had been deducted from capitals gains.

3) Not supper critical but in the full report add a section that lists all the Transfer fees (like you currently do for costs I’ve attached an image of a suitable suggested format).

I understand there may not be enough UK users to justify these added features but for example this current year I have over £500 of transfer fees due to some high eth gas fees. Getting Koinly to account from these correctly (20% tax of £500) would save me a £100 in tax and more than justifies the cost of using Koinly. Also implementing these changes means you would be one of the few services that would be calculating UK taxes correctly.