Tax year and calculation state
The recipient sees the shared tax year, readiness state, unresolved issues, and the calculation or snapshot date that qualifies the figures.
For UK accountants
A crypto tax report you can inspect before you put your name to it.
ChainTax organises supported exchange and DeFi activity into UK tax working, then exposes the source evidence, matching rules, manual interventions, and unresolved checks for your review.
ChainTax prepares calculation evidence. It does not replace your professional judgement, advice, or filing sign-off.
Frozen report snapshotIllustrative calculation, not recipient screen
Disposal working
2.4500 ETH disposed
14 March 2025 · High confidence
- Proceeds
- £6,273.18
- Allowable cost
- £3,055.96
- Fee
- £4.12
- Chargeable gain
- £3,213.10
- Pool before
- 14.8200 ETH
- Pool after
- 12.3700 ETH
Evidence status
Source price, acquisition history, and pool arithmetic checked for this disposal.
What a signed-out recipient actually receives
A bounded report view, not a second dashboard.
The calculation mock-ups on this page explain report working. They are not screenshots of the recipient interface. The authenticated sharing journey supports the recipient facts below.
Snapshot or live-state semantics
The signed-out view identifies whether it is a frozen snapshot or a live report view; a snapshot does not silently change during review.
Read-only report access
Accountant sharing is read-only. The recipient can inspect report totals, manual changes, unresolved evidence, and per-disposal Show Working without editing the client account.
Owner-controlled lifetime
The link shows when it expires and stops working after it is revoked by the owner; revocation is enforced by the server.
Owner-only downloads
Downloads stay with the report owner. The signed-out recipient view is for inspection and does not present the owner’s PDF or CSV download controls.
The review pack
Less reconstruction. More visible evidence.
The engine currently includes 34 protocol-specific classifiers across five EVM chains. Supported rules create the calculation; anything outside the evidence boundary stays named rather than being hidden inside an apparently finished total.
Frozen report snapshot
The client can share a dated, read-only version so the numbers do not shift while you review them.
Per-disposal Show Working
Matching rule, pool movement, proceeds, allowable cost, fees, price source, and confidence are visible.
Named evidence blockers
Missing history, unresolved classifications, unpriced taxable items, and manual interventions remain identifiable.
Return-oriented output
Aggregate totals map to SA108 boxes, with Box 51 handling for the 2024/25 split-year rate change.
Show Working
The calculation trail behind each material disposal.
Every disposal exposes the matching rule, Section 104 pool before and after, proceeds, allowable cost, fees, price source, and confidence. The report separately maps aggregate totals to the SA108 boxes. See an illustrative calculation trail behind the reports.
Positive readiness has a hard gate
A report cannot show “Ready for accountant review” while a material low-confidence item, evidence gap, missing price, or stale rematch remains. The status is a workflow control, not a guarantee of filing correctness.
Frozen report snapshotIllustrative calculation, not recipient screen
Disposal working
2.4500 ETH disposed
14 March 2025 · High confidence
- Proceeds
- £6,273.18
- Allowable cost
- £3,055.96
- Fee
- £4.12
- Chargeable gain
- £3,213.10
- Pool before
- 14.8200 ETH
- Pool after
- 12.3700 ETH
Evidence status
Source price, acquisition history, and pool arithmetic checked for this disposal.
Totals mapped to SA108 boxes 13.1–13.8
Where it fits
A client-prepared evidence layer beside your existing practice workflow.
1
Client prepares the history
They import supported exchange CSVs, connect public wallets, and resolve material checks.
2
ChainTax creates the working
The engine applies supported classification rules and UK matching across the combined history.
3
Client shares a frozen snapshot
You receive the report, evidence status, disposals, income, fees, and calculation trail without dashboard access.
4
You decide what is sufficient
ChainTax organises the evidence; professional judgement and filing sign-off remain with you.
ChainTax is not an accountant practice-management platform. Clients retain their own account and share only the report snapshot they want you to review.
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
Sample material or referral
Review the evidence format before involving a client.
Ask for a sample pack, a methodology answer, or help routing a complex DeFi client. A meeting is optional.
Any ongoing referral arrangement is agreed separately in writing.