The crypto tax tool market is crowded, but most products were built for the US and adapted for the UK as an afterthought. Choosing the wrong one means wrong HMRC figures — and that is a real risk, not a marketing claim. Here is an honest comparison of ten tools available to UK investors.
The single most important criterion for UK users
Before anything else — price, UI, number of integrations — a UK investor needs a tool that applies HMRC's three matching rules correctly and in the right order: same-day acquisitions, then 30-day look-ahead, then the Section 104 average pool. A tool that produces wrong gains is not just unhelpful; it is a liability. Every tool in this list claims to support UK rules, but the quality of implementation varies significantly.
Comparison table
| Tool | UK focus | Free tier | Report price | HMRC matching |
|---|---|---|---|---|
| Polyconomic | UK-only | Full gain, all years, free to view | £49/yr Standard | ✓ All 3 rules |
| Koinly | Global (UK supported) | See gains (capped) | From ~£49/yr sub | ✓ Supported |
| CryptoTaxCalculator | Global (UK supported) | Categorise only | From ~£49/yr sub | ✓ Supported |
| Blockpit | EU (UK supported) | Portfolio overview only | From ~£79/yr sub | ✓ Supported |
| CoinTracker | US (UK supported) | 25 transactions only | From ~£45/yr sub | ✓ Supported |
| TaxBit | US enterprise | Very limited | Enterprise pricing | Partial |
| ZenLedger | US-focused | Preview only | From ~$49/yr USD | Partial |
| TokenTax | US-focused | None | From ~$65/yr USD | Partial |
| Divly | Nordic (EU supported) | Limited | From ~£30/yr sub | ✓ Supported |
| GoSimpleTax | UK tax, not crypto-specific | Basic SA only | From ~£9/yr | Not crypto-specific |
Who should use which tool
For most UK individual investors with exchange-based history, Polyconomic provides the best combination of HMRC accuracy, free access to the gain number, and straightforward pricing. For investors with significant DeFi activity across many chains and protocols, Koinly or CryptoTaxCalculator offer broader transaction detection that may be worth the subscription cost. For investors with holdings across multiple European jurisdictions, Blockpit is worth evaluating.
The free tier test
Before signing up to any tool, find out exactly what the free tier shows you. Ask: “Can I see my total taxable gain for 2023/24 without paying?” Most tools will show you a preview but require payment to see the final number. Polyconomic shows you the full calculation — Section 104 pool, matching adjustments, total gain — before you decide whether you need the downloadable report.
Frequently asked questions
Do all ten tools handle HMRC's Section 104 pool correctly?
The major tools (Koinly, CryptoTaxCalculator, Blockpit, CoinTracker, Polyconomic) all implement Section 104 pooling. The quality of implementation varies — edge cases like bed-and-breakfasting detection and same-day matching are where errors most commonly occur. US-focused tools like TaxBit and ZenLedger treat UK as a secondary jurisdiction and may have gaps.
Is there a free crypto tax tool that actually gives you the full gain for free?
Polyconomic shows your full taxable gain for all tax years without any payment or transaction cap. All other tools in this comparison either cap free-tier transactions, hide the total until you pay, or only show a portfolio overview rather than a tax calculation.
Which tool handles the most exchange integrations for UK users?
Koinly and CryptoTaxCalculator have the broadest exchange and wallet integration libraries. Polyconomic covers Binance, Coinbase, Kraken, and Bybit via API, with CSV import supporting virtually any exchange. For users on more obscure exchanges, Koinly or CTC are worth checking first.
Can any of these tools produce an SA108-ready PDF?
Yes — Polyconomic, Koinly, CryptoTaxCalculator, Blockpit, and CoinTracker all produce downloadable reports that include the figures needed for SA108. Polyconomic's report explicitly labels each figure with the corresponding SA108 box number.
I have both UK and US tax obligations — which tool covers both?
Koinly supports the widest range of countries and is the most commonly used tool by people with multi-jurisdiction obligations. TaxBit is an option for US-side reporting if the portfolio is large enough to justify enterprise pricing.
How often do these tools update their HMRC rule implementations?
This is difficult to verify from the outside. The best approach is to test a known scenario — for example, a same-day buy and sell, or a trade within 30 days of a previous sale — and check whether the tool identifies and handles the matching correctly. Polyconomic was built exclusively around HMRC rules and is updated whenever HMRC guidance changes.
Tool information accurate at time of writing.