A Koinly Alternative for UK Crypto Tax: CryptoCGT vs Koinly (2025/26)

You just want to know what your crypto tax actually is, without handing over your card or connecting every exchange to find out. If you have been looking for a Koinly alternative, you have probably already hit the trade-off: the big tools are powerful and cover dozens of countries, but they want you to create an account, connect your exchanges, and then sit behind a paywall before you can do much with the number. CryptoCGT goes the other way. It does one country, the UK, and it shows you your full Capital Gains Tax figure for free, with no account, before you decide whether to pay anything.

This page is a straight comparison, not a takedown. Koinly is a genuinely good product, and for some people it is the right choice. Below we lay out exactly what each tool costs, what the free tier really gives you, how your data gets in, and what you actually receive at the end, so you can pick the one that fits how you file.

Quick context for 2025/26: in the UK, crypto gains are reported on the SA108 Capital Gains pages of your Self Assessment. The tax-free allowance is £3,000, and gains above it are taxed at 18% (basic-rate band) or 24% (higher/additional), depending on your other income. If you want the full picture first, see our UK crypto tax guide and the 2025/26 rates and allowances.

CryptoCGT vs Koinly at a glance

Here is the honest side-by-side. Competitor figures were checked in June 2026 from Koinly's own pricing and help pages. Prices change, and Koinly lists its plans in US dollars, so please confirm the current number and the GBP conversion on their site before you decide.

The free tier: what each one really gives you

This is the part people get wrong, so let's be precise. Koinly does have a free plan, and it is useful: you can import transactions, track your portfolio, and preview your capital gains and tax liability for free. What you cannot do for free is download the tax report, which needs a paid plan. And to reach the free preview at all, you first create an account.

CryptoCGT's free step is narrower but more open: you upload a CSV (or type entries in) on the homepage calculator and you see your full Capital Gains Tax number immediately, with no account and no signup. You only pay when you want to download the finished SA108. So both tools let you see a number before paying. The honest difference is that with CryptoCGT there is no account, no exchange connection, and no portfolio tracker in the way; it is just the tax calculation.

We want to be fair about this: 'free number' is not a CryptoCGT-only feature, and any page that tells you otherwise is overselling. The real distinction is the combination of a free number with no account, a flat one-off price, and a download that is the actual HMRC form.

How your data gets in: API sync vs CSV-only

Koinly's strength is connectivity. It can pull your history automatically through read-only exchange API keys and public wallet addresses, as well as accept CSV files. If you trade across many venues and want an always-up-to-date portfolio, that auto-sync is a real convenience and it is a fair reason to choose Koinly.

CryptoCGT deliberately does not ask for API keys or wallet connections. You bring a CSV export (or enter trades manually) and that's it. It is a narrower workflow, since you do the export yourself, but it means we never hold a key to your exchange account and there is no connection to revoke later. It is a privacy-and-simplicity trade, not a 'better at everything' claim. If you value hands-off auto-sync over keeping keys off the table, Koinly wins that round.

What you actually file: SA108 vs a report you transcribe

At filing time the question is simple: what do you hand to HMRC? CryptoCGT outputs a filled-in SA108 (the Capital Gains summary pages of Self Assessment) populated with your totals, so the numbers line up with the boxes HMRC expects. Koinly produces a UK Capital Gains tax report/summary that you use to complete your return.

We have not independently verified the exact format of Koinly's UK output (full SA108 vs a summary you transcribe), so we have flagged that for you to confirm on their site rather than state it as fact. The neutral, accurate point is this: CryptoCGT's deliverable is the HMRC form itself; treat any other tool's 'UK report' as something to check against the SA108 boxes.

Accuracy: the part that actually matters for tax

Crypto tax is a 'get-it-wrong-and-it-costs-you' situation, so accuracy is the whole game. CryptoCGT's engine reproduces HMRC's own published worked examples (CRYPTO22251-56) to the penny, including same-day and 30-day bed-and-breakfasting rules, the Section 104 pooled cost basis, fees, and the 2025/26 rates and £3,000 allowance. We also cross-check against the independent open-source BittyTax engine. You can read exactly how the calculation works on our methodology page.

There's a second piece: the reliability gate. If your imported data is incomplete, say a disposal with no matching cost basis, CryptoCGT marks the result provisional and blocks the SA108 download rather than handing you a confident-looking but wrong figure. We would rather tell you 'this isn't ready' than file a number we can't stand behind. Koinly is a mature, widely used tool, but it does not publish HMRC-example reproductions in the same way, so for UK-specific correctness this is where a purpose-built tool earns its keep.

A record of what you actually filed

Here's a quieter issue worth understanding before you pick any crypto tax tool. Your figures are recomputed live from your transaction history. That is usually a good thing, but it means a later import, an edited transaction, or a price-data update can change a number you have already filed with HMRC, often with no copy of what you originally submitted to compare against.

CryptoCGT works differently. When you download your SA108, we save a stamped, dated, locked copy of those exact figures. A later change can never silently rewrite it, and if your figures do move we show you the old and new side-by-side so you can decide whether to file an amendment, while your filed copy stays untouched. You always keep a provable record of the version you filed.

We have not audited how every competitor stores a filed report, so treat this as a question to ask of any tool you compare, Koinly included: if you download your report today and re-sync or re-import next month, can you still see the exact figures you filed, and will the tool tell you they changed? For UK Self Assessment, where you may later need to defend or amend a return, a locked, dated record is worth having.

Who each tool suits

Rather than crown a winner, here's the honest fit for each:

• Choose CryptoCGT if: you file in the UK only, you want to see your real CGT number before paying or signing up, you would rather upload a CSV than hand over exchange API keys, you want a flat one-off price per tax year with back-years bundled, and you want the download to be the actual SA108.
• Choose Koinly if: you need multiple countries, you want exchanges and wallets to auto-sync automatically, you want a year-round portfolio tracker, and you're comfortable creating an account and connecting via API to get there.
• It's a close call if: you're UK-based with a handful of exchanges. Both will let you see a number for free first, so try CryptoCGT's no-account calculator and Koinly's free preview, and go with whichever fits your data and budget.

A note on price

CryptoCGT is a flat £49 per tax year (currently £29 for founding users), charged once, with back-years bundled, and it is not a subscription. Koinly is tiered by how many transactions you have: as of June 2026 its paid plans were listed as Newbie $49 (100 tx) / Hodler $99 (1,000 tx) / Trader from ~$199 (10,000 tx) per year (in US dollars), so your cost depends on your trade count and the GBP exchange rate at checkout.

Because competitor pricing moves and is quoted in dollars, treat the figures above as a snapshot, so check Koinly's current pricing before deciding, and convert to sterling. The fair summary: for a UK filer with a normal number of trades, CryptoCGT's flat sterling price is usually the simpler and often cheaper route, while Koinly may make sense if you're already paying for its broader feature set.

Try it before you pay or sign up

The easiest way to decide is to just see your number. Upload a CSV or type in your trades on our free calculator, with no account, no card, and no exchange connection, and you'll get your full 2025/26 Capital Gains Tax figure in seconds. If it's complete and you want to file, you pay once to download the SA108. If the data isn't complete, we'll tell you that too, rather than guess.

New to UK crypto tax? Start with our UK crypto tax guide and the 2025/26 rates and allowances, then come back and run your numbers.

Sources

• Koinly: pricing plans (koinly.io)
• Koinly: how pricing works (help centre)
• Recap: pricing (UK-built comparison reference)
• CoinLedger: pricing (reference)
• CoinTracker: plans and pricing (reference)
• GOV.UK: Capital Gains Tax rates and allowances
• GOV.UK: SA108 Capital Gains Summary
• HMRC: Cryptoassets Manual (CRYPTO22251 onwards)