Koinly is one of the most widely used crypto tax tools in the world, with genuine UK HMRC support. Polyconomic was built exclusively for UK investors. If you are a UK user trying to choose between them, the decision comes down to three things: how much you want to pay to see your own number, how important UK-specific design is, and whether Koinly's broader exchange coverage matters for your specific portfolio.
Feature comparison
| Feature | Koinly | Polyconomic |
|---|---|---|
| Built for UK HMRC | One of many countries | UK-only |
| Free to see full gain | Limited — report requires payment | Yes — all years, no cap |
| Report pricing | ~£49/yr subscription | £49/yr Standard · £99/yr Pro |
| HMRC matching rules | ✓ Supported | ✓ Applied by default |
| API connections | Very broad (400+) | Binance, Coinbase, Kraken, Bybit |
| CSV import | ✓ | ✓ |
| ETH/BTC wallet import | ✓ | ✓ |
| SA108-compatible report | ✓ | ✓ |
| Plain English output | Standard | Yes — UK-specific language throughout |
| Accountant multi-client | ✓ (paid plan) | ✓ (included) |
| DeFi support | Strong | Standard |
The key practical difference: paying to see your number
The most meaningful difference for most UK investors is not DeFi support or exchange integrations — it is whether you have to pay before you can see what you actually owe. With Koinly, a paid plan is required to generate the report that shows your total taxable gain. With Polyconomic, the full calculation — Section 104 pool, matching adjustments, net gain by tax year — is visible for free. The Standard plan at £49/year gives you the SA108-compatible PDF for filing.
A realistic cost example
A UK investor with 300 trades across Binance and Coinbase: Koinly charges approximately £49/year whether or not you owe any tax, and requires payment before showing your gain. Polyconomic shows the full gain for free. If the gain is below £3,000 and no report is needed for filing, the total Polyconomic cost is £0. If the report is needed, Standard is £49/year — the same price as Koinly, but with free visibility first.
Which should you choose?
Choose Koinly if: your exchanges or wallets go beyond Binance, Coinbase, Kraken, and Bybit — and they do not offer CSV export. Koinly's 400+ integrations are a genuine advantage here. Also choose Koinly if you have complex DeFi history requiring broad on-chain support, or if you need to file in multiple countries simultaneously.
Choose Polyconomic if: your exchanges are among the four covered via API (or you have CSV), you want to verify your position before paying anything, you want a tool designed from the ground up around HMRC's specific rules rather than a global tool with a UK mode, or you want to avoid an annual subscription for a calculation you only need once a year.
Frequently asked questions
Does Koinly apply HMRC matching rules correctly?
Koinly implements the UK matching rules (same-day, 30-day, Section 104) as part of its UK country mode. The implementation is generally considered reliable. However, because UK rules are one of many modes in a globally-designed tool, edge cases are worth verifying — particularly bed-and-breakfasting detection across large transaction volumes.
Can I try both tools and compare results?
Yes. Import the same transaction history into both tools using the same source CSVs or API connections, and compare the Section 104 pool balance and net gain figures. Any significant discrepancy is worth investigating before filing. This is the most reliable way to validate either tool's output.
Does Polyconomic have a DeFi mode or on-chain support beyond ETH and BTC?
Polyconomic currently supports ETH and BTC wallet imports with on-chain transaction detection. Standard DeFi activity (staking, straightforward protocol interactions) is handled. For complex multi-protocol, multi-chain DeFi, Koinly or CryptoTaxCalculator have broader support.
What happens if I overpay with Koinly and my gain turns out to be zero?
Koinly charges a subscription fee regardless of whether you owe tax. If you import your history and find your net gain is below £3,000, you have still paid for the tool. Polyconomic only charges when you download the report — if you owe nothing and do not need the PDF, you pay nothing.
I already paid for Koinly this year — should I switch mid-year?
If you have already paid for Koinly's annual subscription, switching mid-year costs you more overall. Completing this year with Koinly and evaluating alternatives at renewal is more economical. Export your full transaction history from Koinly before the subscription lapses.
Which tool is better for an accountant managing multiple clients?
Both tools have accountant-specific features. Polyconomic includes client access as part of the standard product rather than charging an additional accountant tier fee. Koinly's accountant plan has a separate pricing structure. For a practice with multiple UK-only clients, Polyconomic's per-report pricing is typically more cost-effective at scale.
Tool information accurate at time of writing.