Koinly is the breadth-and-attribution pick of the UK crypto-tax cohort. It is the universal “most popular UK pick” across r/UKPersonalFinance and the UK crypto guides, it carries the broadest integration coverage in the cohort — 700+ exchanges, wallets, and 170 blockchains — and it holds the one structural advantage no UK competitor matches: a 90-day cookie, three times the cohort’s 30-day default. That cookie is why our 12-month EPC lands at $2.83, ranking Koinly #3 at grade B+, on a base commission lower than several names below it. Unlike a crypto exchange or a prop firm, a crypto-tax tool is software, not a regulated financial product — so the compliance burden here is lighter, but the affiliate disclosure is the same: FintechPays earns a commission if you sign through our link, and it does not move the rank.
This review is the editorial wedge for FintechPays’ UK crypto-tax coverage. The category is dominated by “best crypto tax software UK” listicles that rank on brand familiarity and ignore the two things that actually drive affiliate return — the cookie window and the conversion economics. Decoding both, and weighing Koinly’s breadth against Recap’s UK-incorporation moat, is the gap we fill.
Who this is actually for
Koinly is built for affiliates serving the mainstream UK crypto audience — HMRC Self Assessment filers with multi-platform histories, the r/UKPersonalFinance and r/CryptoUK readerships, and the UK accountancy practices that need a tool covering every venue a client touched. Its defining strength for that audience is coverage: a UK investor who traded across several exchanges, moved coins to wallets, and dabbled in DeFi needs a tool that ingests all of it, and Koinly’s 700+ integrations make it the safe “it will handle your history” recommendation.
The audience fit is strongest precisely where reconciliation is hardest — the multi-platform filer who, under the new CARF reporting regime, now has to match a sprawling history against data HMRC receives directly. Where Koinly is the second-best fit is the UK investor who leads with domestic trust or data privacy; that reader converts better on Recap’s UK-built, end-to-end-encrypted positioning, and an honest comparison should route them accordingly.
The commission economics, decoded
We carry base_payout $31.42 — a 25% commission on the £99 Hodler median tier × the ~$1.27 GBP→USD rate. UK affiliate-driven conversions skew toward the Hodler (£99) and Trader (£179) tiers; the Pro (£319) tier is direct-search dominated. We use the conservative 25% rate: the 20% recurring uplift applies in year two, outside the 12-month EPC window, and the 40% top tier requires a negotiated volume agreement rather than being the default, so both are excluded from the base.
The EPC formula then runs cookie_decay 0.75 (the 90-day Impact cookie — the hero), attribution_factor 1.0 (no own-funnel paid-search displacement), reliability_factor 1.0 (no documented non-payment), conversion_rate_estimate 0.12 (crypto-tax niche midpoint), payment_threshold_friction 1.0.
$31.42 × 0.75 × 1.0 × 1.0 × 0.12 = $2.83 of projected 12-month EPC.
The whole story is in that 0.75. Koinly’s 90-day cookie is the only non-30-day window in the UK cohort, and it nearly compensates for a base payout that is modest by category standards: where Recap and the rest decay to 0.55, Koinly holds 0.75, a 0.20 swing that lifts the EPC well above what its £31 base would otherwise produce. Crypto-tax buying is a considered, deadline-driven decision — a UK investor researches in January and buys before the Self Assessment deadline — so a 90-day window captures the gap between discovery and purchase in a way the 30-day cohort cannot. For evergreen UK tax content that ranks ahead of the filing season, that is a genuine structural edge.
The cookie also rewards a particular content shape, and it is worth building for. A 30-day window pushes you toward last-minute, deadline-panic content that converts the reader who is filing this week; Koinly’s 90-day window rewards evergreen reference content — a thorough “how UK crypto tax works” or “best crypto tax software for UK investors” guide — that earns the click early in the research journey and is still holding a live cookie when the reader finally subscribes weeks later, often as the CARF reporting reality sinks in. Pair that with Koinly’s breadth: in a world where HMRC now receives platform data directly, the value of a tool that ingests every venue a reader touched rises sharply, because the cost of missing one — an unreconciled exchange, a forgotten wallet — is a mismatch HMRC can see. Koinly’s 700+ integrations are the structural answer to exactly the anxiety CARF created, and content that connects the breadth to the new reporting reality converts better than a feature list.
Cookie window and attribution honesty
The 90-day Impact Network cookie is Koinly’s defining feature, it is genuinely published (on koinly.io/affiliate and Impact’s network listing), and the EPC already prices it at 0.75. The attribution_factor of 1.0 is clean — Koinly does not run the aggressive brand-term paid-search that would contest affiliate cookies. The honest trade-off is the network layer: attribution runs through Impact, which adds a platform between publisher and programme. Impact is reliable and standard, but it is a layer Recap’s direct programme does not have, and it is worth an affiliate weighing the marginally simpler direct relationship against Koinly’s longer window.
Payout reliability — the data, not the marketing
We rate reliability_factor 1.0, undegraded. Koinly has operated since 2018, runs Impact-managed payouts cleanly on Net 30, and carries no documented affiliate non-payment complaints. The end-user reputation is strong: Trustpilot 4.7/5 across roughly 1,200 reviews, tied for the highest trust score in the UK cohort. For a tool whose entire job is producing numbers an investor will file with HMRC, that reputation is the relevant signal — a tool readers trust to get their tax right produces fewer refunds, fewer complaints, and a cleaner affiliate relationship.
HMRC rule coverage and UK compliance
This is where a crypto-tax review’s diligence shows, because the product’s value is precisely whether it gets HMRC’s rules right. Koinly’s UK report applies the HMRC Cryptoassets Manual mechanics automatically: it builds the Section 104 pool, applies the same-day and 30-day rules, and exports in the UK Self Assessment SA108 (and SA106) formats. That auto-application is the feature that justifies the subscription — reconstructing those pools by hand across 700+ possible venues is exactly the error-prone task the software removes — and content should describe it accurately rather than overclaim it as tax advice.
On regulatory framing: Koinly is not financial-regulated — it is a Norway-incorporated software vendor, not a financial-services firm, and content should not imply otherwise. The FCA’s crypto financial-promotions regime applies to promotions of crypto investments and exchanges; a tax-reporting tool is a step removed, but UK affiliate content should still carry clear affiliate disclosure and frame any tax discussion as general information, not advice — pointing readers to a qualified UK adviser or HMRC for their specific position.
What the programme does better than anyone else
Three things Koinly owns. First, the 90-day cookie — the only non-30-day window in the cohort and the structural attribution advantage for deadline-driven crypto-tax content. Second, coverage breadth: 700+ integrations across 170 blockchains is the cohort’s widest, making it the safe “it will handle your history” pick for multi-platform UK filers. Third, SERP and community position: the universal “most popular UK pick,” which means brand familiarity does real conversion work. For the mainstream, multi-platform UK audience, Koinly is the default recommendation.
Where it falls short
The base commission is modest — a 20–25% ladder on GBP-converted pricing, lower than the flat-rate alternatives, which is the reason the 90-day cookie has to do so much of the EPC work. The Norway HQ means no Companies House visibility, a softer UK trust signal than Recap’s UK-incorporation moat. The pricing is GBP-converted rather than GBP-native, a small FX nuance for UK readers. And the 40% headline top tier is negotiated-only, so content quoting it as the standard rate would mislead.
How it sits in the UK cohort
Koinly and Recap are the cohort’s defining pair, and they split cleanly: Koinly is the breadth-and-attribution pick, Recap is the UK-native trust pick. Koinly wins on cookie length, integration coverage, and brand recognition; Recap wins on UK incorporation, GBP-native economics, native HMRC rule application, and a privacy posture, and it edges Koinly on EPC ($3.40 to $2.83) on the strength of a UK-conversion uplift despite the shorter cookie. The honest editorial move is not “Koinly or Recap” but audience routing: Koinly for the multi-platform mainstream filer who needs maximum coverage, Recap for the reader who leads with UK trust or data privacy — and a comparison page that frames both will outperform either review alone.
Verdict
Make Koinly your default UK crypto-tax recommendation for the mainstream, multi-platform audience — it is the most popular pick for good reason, the 700+ integrations make it the safe choice for a messy multi-venue history, and the 90-day cookie is a genuine structural advantage for evergreen tax content that ranks ahead of filing season. Model the conservative 25% rate, not the negotiated 40% ceiling, and let the cookie carry the economics. Route the UK-trust-first and privacy-first readers to Recap, where they convert better. Two things to keep honest: describe the HMRC rule auto-application (Section 104, same-day, 30-day) accurately without overclaiming it as tax advice, and frame all tax discussion as general information that points to a qualified adviser. Get the audience match right and Koinly is the most dependable volume relationship in UK crypto tax.
Editor’s notes
base_payout $31.42 = 25% × £99 Hodler median × ~$1.27 GBP→USD. UK conversions skew Hodler/Trader; Pro is direct-search dominated. Conservative 25% rate (20% recurring uplift is year-2, outside the 12-month window; 40% top tier negotiated, excluded). cookie_decay 0.75 — 90-day Impact Network cookie published on koinly.io/affiliate and Impact’s listing (per EPC spec, 90d → 0.75); the structural attribution edge over the 30-day cohort. attribution_factor 1.0 (no own-funnel displacement). reliability_factor 1.0 (since 2018, clean Impact payouts). conversion_rate_estimate 0.12 (niche midpoint). Flag: none. Compliance: not financial-regulated (Norway-incorporated software vendor); HMRC Section 104 / same-day / 30-day auto-application certified; FCA crypto-promotions regime applies to crypto-investment promotion (a tax tool is a step removed) — carry affiliate disclosure, frame tax as general information not advice. Fact-check (a-devi): 90-day cookie, Impact Network, 20–25% ladder confirmed against koinly.io/affiliate as of 2026-05-14; GBP-converted UK pricing (£49/£99/£179/£319) verified; HMRC rule auto-application confirmed via Koinly UK tax-report documentation; Trustpilot 4.7/5 across ~1,200 reviews verified.