Pay once for the tax year you need.
Light and Active use the same calculations, review checks, Show Working, and report downloads. The only difference is transaction capacity.
Start with 200 transaction records account-wide · No card · No automatic renewal
What counts as a transaction record?
Transaction-record capacity is account-wide. A record is a unique on-chain transaction or a supported CSV or manual record that reaches your account history, whether taxable or not. Duplicates are removed before counting; ignored or unsupported rows do not count. Wallet activity counts when it is stored as a unique on-chain transaction. Reaching the limit pauses additional imports and wallet processing until a higher one-off tax-year tier is unlocked. Every tier uses the same calculation rules and quality.
Capacity and report access are separate: the highest tier you have purchased sets account-wide transaction-record capacity, while each one-off purchase unlocks report access only for its selected UK tax year. Capacity does not reset when the tax-year selector changes.
Every paid plan includes
Same UK calculation
Same-day, 30-day and Section 104 matching do not change by tier.
Same review checks
Missing history, prices and unclear material items stay visible in both plans.
Same report outputs
PDF, CSV, SA108 box values and per-disposal Show Working are included.
Over 10,000 transaction records account-wide?
We'll run a Concierge sync for you. Quote-first, no commitment.
Questions? hello@chaintax.co.uk. We typically reply within a few hours.
Filing 2025/26 & 2026/27?
Get both tax years in one checkout and save.
Light
£98 separately
Active
£198 separately
Bundle covers 2025/26 and 2026/27. Already purchased one year? Buy each year individually to upgrade.
Important boundaries and manual checks
These are calculation boundaries, current-law choices, and coverage gaps to review before relying on a report.
- •stETH rebases: ChainTax estimates rebase income from periodic wallet-balance snapshots (monthly and at tax-year boundaries), net of transfers, then values the increase on the snapshot date. This covers every fully synced Ethereum wallet on the account, but it is not a daily receipt-by-receipt reconstruction.
- •Receipt-token deposits: For supported Aave, Compound V2, Yearn, and Convex actions, ChainTax currently treats decoded deposits and withdrawals as transfers and carries Section 104 basis when both economic legs are present. Missing required legs are sent to Needs review. EigenLayer automation covers StrategyManager LST restaking, not native-ETH EigenPod restaking. HMRC's current CRYPTO61620 treatment depends on beneficial ownership and can treat a token exchange as a disposal. Draft NGNL rules were published on 13 July 2026 for qualifying arrangements from 6 April 2027, but are not yet law. Ask a tax adviser before changing current-period treatment.
- •Internal ETH returns: Known Rocket Pool and cbETH methods use trace data to recover ETH returned through internal calls; if that data is unavailable, the event stays in Needs review. Nexus Mutual sales can instead use the NXM market value as a fallback, and the event note says when that happened.
- •Chain coverage: Automatic on-chain sync supports Ethereum, Arbitrum, Optimism, Base, and Polygon. Other networks, including Solana and Avalanche, need a supported CSV import or manual records.
Full detail: How it works → Important boundaries
Public addresses only. No private keys, signatures, or permission to move funds.
Same-day, 30-day and Section 104 matching are applied across your combined history.
Open the calculation to see proceeds, matched cost, fees, price evidence and pool movement.
Incomplete history, prices or unclear activity cannot quietly become a positive review state.
Common questions
Which tax rules does ChainTax apply?
All three HMRC matching rules: same-day, 30-day bed-and-breakfast, and Section 104 pooling (average cost basis). ChainTax carries basis for supported same-owner, same-asset bridges and direct ETH→WETH wraps where the evidence preserves ownership and asset rights. CGT runs at 18%/24% for 2025/26 and 2026/27 disposals; 2024/25 was the one split year, taxed at 10%/20% before 30 Oct 2024 and 18%/24% after, applied per disposal.
What do I get for free?
Import exchange CSVs or connect your wallets and classify up to 200 transaction records account-wide. View your report summary, classifications with confidence ratings, and Show Working. PDF and CSV downloads require a purchase for the selected tax year.
Can I upgrade later?
Yes. Buy Light now and upgrade to Active later, and you only pay the difference. Your data stays intact.
What if a classification looks wrong before I file?
You can manually edit transactions before downloading your report, including the tax type and notes for anything that needs an override. If you are unsure, email hello@chaintax.co.uk and we will help you check it before you file.
Why per tax year, not a subscription?
You file once per year, so you pay once per year. Each purchase covers one UK tax year (6 April to 5 April). No recurring charges, no auto-renewals.
Which chains and exchanges are supported?
On-chain wallet scanning for Ethereum, Arbitrum, Optimism, Base, and Polygon. CSV import: Coinbase, Binance and Kraken; Crypto.com App (beta); plus Koinly universal CSV (compatible format). The Crypto.com App importer is in beta. It is parser-tested but has not yet been validated end to end against a current real export, so review the imported rows before relying on them. On-chain activity from non-EVM chains is not classified automatically.
How does this compare to an accountant?
ChainTax organises supported exchange and DeFi activity and shows the calculation trail. It does not replace professional advice or an accountant's sign-off. Accountant fees and review time vary with the portfolio and the quality of the source data.
What happens if HMRC changes the SA108 format?
We update ChainTax each tax year to match the latest HMRC guidance. When HMRC introduced dedicated crypto boxes (13.1–13.8) on SA108 for 2024/25, we shipped support on day one, including the split-year CGT rate change. Future format changes will be handled the same way.
Further reading
Switching from another tool?