Links marked (Ad) are affiliate links: FiscalFox may earn a commission if you buy Koinly through them, at no extra cost to you. FiscalFox also imports Koinly's Capital Gains Report, which is why we looked at it closely.
Our verdict: for UK investors, Koinly is a sound choice for working out crypto gains. It applies HMRC's matching rules, shows you which rule matched every line, and lets you see your gains for free before you pay. What it does not do is shares. If you sold shares as well, you need its report and your broker history in one place, which is what FiscalFox's Koinly import is for.
This review is based on a real 2025/26 Koinly UK Capital Gains Report from one of our own accounts (459 lines covering 169 disposals), Koinly's published documentation, and its pricing page on 9 October 2026.
What works well for UK users
- Names the same-day, 30-day and Section 104 rules for the UK, and labels every report line with the rule that matched it
- Free to import and preview your gains before you pay
- Priced per tax year, with over 900 exchange and wallet integrations
- Separate Income Report for staking, airdrops and interest
What to watch
- Crypto only: it does not calculate gains on shares or funds from your broker
- One CSV line per matched portion, so the line count is not the SA108 disposal count
- Missing cost basis lines need fixing in Koinly, or the whole proceeds are taxed
- Prices on its pricing page are shown in US dollars
Does Koinly apply HMRC's rules?
HMRC requires each crypto sale to be matched first with tokens of the same type bought on the same day, then with tokens bought in the following 30 days, and only then with a pool at average cost (CRYPTO22200). Koinly says its UK method supports "Share Pooling", "including same-day and bed-and-breakfasting rules" (koinly.io/gb).
The report backs that up. Every line in the Notes column names the rule that matched it, so you can check the order yourself rather than take it on trust. In the report we looked at, lines were labelled with all three rules.
Capital gains report 2025 - 26
| Column | What it holds |
|---|---|
| Date Sold | Date and time of the disposal (DD/MM/YYYY HH:MM) |
| Date Acquired | Often blank on Section 104 pool lines, since a pool has no single purchase date |
| Asset | The token, for example BTC or ETH |
| Amount | Units in this matched portion of the sale |
| Cost (GBP) | Allowable cost matched to those units |
| Proceeds (GBP) | Sale value of those units in pounds |
| Gain / loss | Proceeds less cost for the line |
| Notes | Which HMRC rule matched the line, and flags such as Fee or Missing cost basis |
| Wallet Name | The exchange or wallet the sale came from |
A few notes carry extra flags. Fee marks tokens spent on network or trading fees, which count as small disposals. Missing cost basis marks a sale where Koinly found no purchase, covered below.
Settings to check before you download
- Country and currency: United Kingdom and GBP, so the report runs 6 April to 5 April in pounds.
- Cost basis method: Share Pooling. Koinly once had a "Share Pooling [Legacy]" method that handled same-day trades as FIFO, fixed in 2021 with a switch to "Share Pooling / Individuals" (Koinly forum). If your account is that old, check which one is selected.
- Every source connected: include crypto held at brokers such as eToro, and any wallet tokens were sent from. Missing sources are the usual cause of missing cost basis.
Missing cost basis: fix it before you file
When Koinly sees tokens leave but never saw them arrive, it has no cost for the sale. The line is marked Missing cost basis and the cost is nil, so the whole proceeds count as gain. That is the safe treatment for HMRC but often overstates your tax. Connect the wallet or exchange the tokens came from, or add the purchase by hand, then download the report again. FiscalFox treats any line still marked this way the same way, taxes the full proceeds and tells you which lines they are.
Getting the SA108 figures right
From 2024/25 crypto goes in the SA108 Cryptoassets section, boxes 13.1 to 13.8 (SA108 2026). Two things trip people up with the CSV:
- Lines are not disposals. One sale matched partly against the same day and partly against the pool becomes two lines. Box 13.1 asks for the number of disposals. The report we looked at had 459 lines but 169 disposals.
- Rounding. Each line is rounded to the penny, so a total added up from the lines can be a few pence away from Koinly's own summary. In our report the gap was 4p. That is normal and not worth chasing.
For 2023/24 onwards you must fill in the SA108 if your disposal proceeds were over £50,000 or your gains were over the annual exempt amount (GOV.UK), and swaps between tokens count towards proceeds.
What Koinly costs
Importing and previewing is free. To download reports you buy a plan for the tax year, sized by the number of transactions. On 9 October 2026 Koinly's pricing page showed $49 for up to 100 transactions, $99 for up to 1,000 and $199 for 3,000 or more, as one-off payments rather than a subscription (Koinly pricing). Check the page for the current price in pounds before you buy.
Koinly and shares on one return
The annual exempt amount and your losses apply to crypto and shares together. Koinly only sees the crypto. If you also sold shares or funds, upload your broker exports to FiscalFox, then add the Koinly Capital Gains Report CSV unedited. FiscalFox runs your shares through the same-day, 30-day and Section 104 rules, reports each Koinly line as Koinly matched it, and gives you one SA108 schedule. If a coin appears in both Koinly and a broker file, FiscalFox asks before counting it once. The full walkthrough is in crypto and shares on one SA108, and our comparison covers the alternatives.
Already have your Koinly report?
Upload your broker exports to the free calculator, then add the Capital Gains Report CSV. The calculation is free.
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Export steps for each brokerFrequently asked questions
Is Koinly HMRC compliant?
HMRC does not approve or endorse any crypto tax software. Koinly says its UK share pooling method applies the same-day and bed and breakfast (30-day) rules, and its UK Capital Gains Report labels each line with the rule that matched it: Same day pool, Bnb rule pool or Section 104 pool. You are still responsible for the figures, so check missing cost basis lines and connect every wallet.
How much does Koinly cost in the UK?
Importing transactions and previewing your gains is free. To download tax reports you buy a plan for the tax year. On 9 October 2026 Koinly's pricing page showed plans from $49 for up to 100 transactions, $99 for up to 1,000 and $199 for 3,000 or more, as one-off payments per tax year.
Which Koinly report do I need for the SA108?
The Capital Gains Report gives the disposals for the Cryptoassets section, boxes 13.1 to 13.8 from 2024/25. Count disposals rather than CSV lines for box 13.1, because Koinly writes one line for each matched portion of a sale. Staking and other crypto income is in the separate Income Report.
Can I use Koinly for shares as well as crypto?
Koinly is built for crypto and does not calculate gains on shares or funds from broker exports. If you also sold shares, upload your broker files to FiscalFox and add the Koinly Capital Gains Report, and FiscalFox puts both on one SA108 with one annual exempt amount.
What does Missing cost basis mean in Koinly?
Koinly found a sale but no purchase for those tokens, usually because they arrived from a wallet or exchange you have not connected. Until you fix it, the cost is nil and the whole proceeds count as gain. Connect the missing source or add the purchase, then download the report again.
Official UK tax references
This guide is checked against published GOV.UK and HMRC material. FiscalFox is a calculation tool, not personal tax advice; review unusual transactions with a qualified adviser.