Sources checked 9 November 2026. Deadlines below are the general rules; your own dates depend on your accounting period and entity type. This page is general education for a UK or US company that holds bitcoin. It is not legal, tax, accounting or investment advice, and it does not say whether to buy, hold or sell. If anything here conflicts with the linked source, the source wins.
Short answer
A clean year end for a company holding bitcoin comes down to four things: a holdings reconciliation at the exact reporting date, a documented price source and time, evidence that the company controls the keys, and a complete list of every acquisition, disposal and fee in the period. Then the country rules take over: Companies House and HMRC deadlines in the UK, and the federal return, Form 8949 and any Form 1099-DA in the US. Start the evidence pack in December, before exchange statements and staff memories fade.
For every company: the core year-end pack
These steps apply whichever country you file in. Tick them off and keep the outputs in one dated folder.
- Freeze the date and time. Agree the reporting date and the exact time (for example 23:59 UK time) at which balances and prices are taken. Use the same convention every year.
- Reconcile units. For each wallet and each custodian or exchange account, record the number of bitcoin at that time and tie it to the ledger. Explain any difference before the accounts are drafted.
- Evidence control, not just balances. A watch only wallet view, a signed message or a custodian statement shows the bitcoin exists; a recent recovery drill shows the company can still move it. See audit evidence and the recovery drill.
- Record the price source. Name the exchange or index, the time and the rate used, and keep a screenshot or export. HMRC and US auditors both expect a consistent, documented method.
- List every movement. Purchases, sales, payments received or made in bitcoin, network fees paid in bitcoin and transfers between the company's own wallets, with transaction IDs.
- Download provider records now. Export full transaction histories and year-end statements from every exchange and custodian. Providers can close accounts or limit history later.
- Check the policy was followed. Compare the year's activity with the board's treasury policy: caps, approvals, signers and sell triggers. Minute any exceptions.
- Review keyholders. Confirm who holds each key or approval, whether anyone has left, and that the handover record is current. See keyholder continuity.
- Brief the accountant early. Send the reconciliation, price evidence and movement list with the trial balance, not after it. The bookkeeping examples and workbook show a layout.
Never move bitcoin just to prove it exists at year end. A test transaction adds fees and risk; signed messages and watch only views avoid both.
Country rules differ for deadlines, accounts and tax. Choose your country.
The short version: UK
- Accounts go to Companies House 9 months after the year end (21 months from registration for the first accounts).
- Corporation Tax is usually payable 9 months and 1 day after the end of the accounting period; the CT600 is due 12 months after it.
- Holding bitcoin rarely changes those dates, but it adds a valuation and impairment review, and a chargeable gains computation for any disposal.
UK: the dated deadlines
| What | General rule | Year end 31 March 2026 | Year end 31 December 2026 |
|---|---|---|---|
| Accounts to Companies House | 9 months after the year end | 31 December 2026 | 30 September 2027 |
| Corporation Tax payment (taxable profits up to £1.5 million) | 9 months and 1 day after the end of the accounting period | 1 January 2027 | 1 October 2027 |
| Company Tax Return (CT600) to HMRC | 12 months after the end of the accounting period | 31 March 2027 | 31 December 2027 |
Larger companies pay Corporation Tax in instalments instead. A first accounting period, a change of year end or a period longer than 12 months changes the dates, so confirm them with your accountant or your Companies House and HMRC accounts.
Source: GOV.UK: Accounts and tax returns for private limited companies: deadlines (first accounts 21 months, then 9 months), GOV.UK: Company Tax Returns: deadlines (12 months to file, payment usually 9 months and 1 day), GOV.UK: Pay your Corporation Tax bill: deadlines by size of taxable profits.
Late accounts carry automatic Companies House penalties for a private company, from £150 up to £1,500 depending on how late, doubled if accounts are late two years running.
Source: GOV.UK: Prepare annual accounts: penalties for late filing.
UK: the accounts at the reporting date
- FRS 105 (micro-entities): historical cost only. Check for impairment at the reporting date; a fall in value can mean a write-down, a rise is not recognised.
- FRS 102, including Section 1A: the cost model with an impairment review, or the revaluation model where fair value can be found by reference to an active market. Whether bitcoin's market meets that test is a judgement for your accountant.
- Size: a company is small with any two of turnover up to £15 million, balance sheet up to £7.5 million and up to 50 employees; a micro-entity with any two of £1 million, £500,000 and 10 employees.
Source: GOV.UK: Prepare annual accounts: micro-entities, small and dormant companies (size thresholds).
The detail is on FRS 105 and bitcoin and FRS 102 and bitcoin. The UK year-end page covers the CT600 and records in more depth.
UK: Corporation Tax and records
HMRC's view is that a company's bitcoin is usually taxed under the chargeable gains rules when it is disposed of, because tokens simply held do not meet the definition of an intangible fixed asset. Gains and losses go in the chargeable gains boxes of the CT600. Keep records for at least 6 years from the end of the financial year they relate to.
Source: HMRC: CRYPTO41150: Corporation Tax, intangible fixed assets (tokens simply held are not intangible fixed assets), HMRC: Company Tax Return form CT600 (2026) Version 3, boxes 210 to 220 for chargeable gains (PDF, page last updated 1 April 2026), GOV.UK: Running a limited company: company and accounting records (keep for 6 years).
UK: what is changing
- Cryptoasset Reporting Framework: UK crypto providers have collected due diligence information since 1 January 2026. A company customer must give its provider the details asked for, including about its controlling persons, or risk a penalty and loss of service.
- Accounts filing from 1 April 2028: all companies must file accounts through commercial software in iXBRL. On 23 October 2026 the government paused the plan to make small and micro companies file a profit and loss account; abridged and filleted accounts stay available for now.
Source: HMRC: CRYPTO49000: Cryptoasset Reporting Framework, including business customers of a provider, Companies House: Companies House update to accounts filing from April 2028 (published 23 October 2026), Companies House: Using software to file your company's information (software only accounts filing from 1 April 2028).
The short version: US
- A C corporation files Form 1120 by the 15th day of the 4th month after its year end; an S corporation files Form 1120-S by the 15th day of the 3rd month.
- Both returns ask the digital asset question, and disposals are reported on Form 8949 and Schedule D whether or not a broker sends a form.
- Many C corporations are exempt recipients, so a Form 1099-DA may never arrive. Your own records are the return.
US: the dated deadlines
| What | General rule | Calendar year 2026 |
|---|---|---|
| Form 1099-DA statements from brokers (where issued) | Furnished by mid-February; the 2025 forms were due 17 February 2026 | Mid-February 2027; check the 2026 General Instructions for the exact date |
| Form 1120-S (S corporation) | 15th day of the 3rd month after the year end | 15 March 2027 |
| Form 1120 (C corporation) | 15th day of the 4th month after the year end (June 30 year ends have a different rule) | 15 April 2027 |
Extensions to file are not extensions to pay. State returns have their own dates.
Source: IRS: General Instructions for Certain Information Returns (2025): due dates for Form 1099-DA statements, IRS: Instructions for Form 1120 (2025): when to file and the digital asset question, IRS: Instructions for Form 1120-S (2025): when to file.
US: accounts at the reporting date
Under ASU 2023-08, in scope crypto assets such as bitcoin are measured at fair value at each reporting date, with changes in net income, for fiscal years beginning after 15 December 2024. A calendar year company therefore applies it to its 2025 and 2026 year ends. Keep the principal market analysis, the price and time used, and the roll forward of cost, fair value and units that the disclosures need. See US accounting under ASU 2023-08.
Source: FASB: ASU 2023-08, Intangibles: Goodwill and Other, Crypto Assets (Subtopic 350-60).
US: tax return and records
- Answer the digital asset question on Form 1120 or 1120-S. It is "Yes" if the company received bitcoin as payment or reward, or sold, exchanged or otherwise disposed of any, during the year.
- Report every disposal on Form 8949 and Schedule D, using your own lot records. A Form 1099-DA, if one arrives, is a cross check, not the source.
- Identify units wallet by wallet. Since 1 January 2025, basis is tracked per wallet or account. The temporary broker relief in Notice 2025-07 covered 2025 only.
- Keep the records that support each figure for as long as they may be needed, generally at least 3 years from filing and longer in some cases.
Source: IRS: Instructions for Form 1120 (2025): when to file and the digital asset question, IRS: About Form 8949, Sales and Other Dispositions of Capital Assets, IRS: Notice 2025-07: temporary relief for identifying units held by a broker, ended 31 December 2025 (PDF), IRS: Revenue Procedure 2024-28: allocating unused basis to wallets and accounts as of 1 January 2025 (PDF), IRS: How long should I keep records?.
The Form 1099-DA page explains which companies receive one and what it shows; the glossary entry gives the short definition.
Open points to check with your adviser
- UK: whether the revaluation model is available to you; how any impairment or revaluation interacts with distributable profits; whether any activity could be a trade rather than an investment.
- US: entity classification for an LLC; state tax treatment; whether your auditor accepts your principal market and cut-off time; how any 2026 basis reporting by your broker compares with your own lots.
Read next
- UK year end: CT600, accounts and records, the UK detail.
- Form 1099-DA for companies, what a US company may receive.
- Audit evidence, proving control without moving funds.
- Company tax on bitcoin, UK and US rules for disposals.
- Bookkeeping worked examples, with a workbook.
Sources
Primary sources only. Each link was checked on 9 November 2026. Rules change, so confirm the current version with your adviser.
- GOV.UKAccounts and tax returns for private limited companies: deadlines (first accounts 21 months, then 9 months)
- GOV.UKCompany Tax Returns: deadlines (12 months to file, payment usually 9 months and 1 day)
- GOV.UKPay your Corporation Tax bill: deadlines by size of taxable profits
- GOV.UKPrepare annual accounts: penalties for late filing
- GOV.UKPrepare annual accounts: micro-entities, small and dormant companies (size thresholds)
- HMRCCRYPTO41150: Corporation Tax, intangible fixed assets (tokens simply held are not intangible fixed assets)
- HMRCCompany Tax Return form CT600 (2026) Version 3, boxes 210 to 220 for chargeable gains (PDF, page last updated 1 April 2026)
- GOV.UKRunning a limited company: company and accounting records (keep for 6 years)
- HMRCCRYPTO49000: Cryptoasset Reporting Framework, including business customers of a provider
- Companies HouseCompanies House update to accounts filing from April 2028 (published 23 October 2026)
- Companies HouseUsing software to file your company's information (software only accounts filing from 1 April 2028)
- IRSGeneral Instructions for Certain Information Returns (2025): due dates for Form 1099-DA statements
- IRSInstructions for Form 1120 (2025): when to file and the digital asset question
- IRSInstructions for Form 1120-S (2025): when to file
- FASBASU 2023-08, Intangibles: Goodwill and Other, Crypto Assets (Subtopic 350-60)
- IRSAbout Form 8949, Sales and Other Dispositions of Capital Assets
- IRSNotice 2025-07: temporary relief for identifying units held by a broker, ended 31 December 2025 (PDF)
- IRSRevenue Procedure 2024-28: allocating unused basis to wallets and accounts as of 1 January 2025 (PDF)
- IRSHow long should I keep records?
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This is general information and education only. It is not financial, investment, tax, accounting, legal or regulatory advice, and it is not a recommendation to buy, sell or hold bitcoin or any other asset. It does not take account of your circumstances or those of your company. You must obtain your own official professional advice to confirm this information is correct before acting on it.
Rules change. This information is correct to our understanding at the last-reviewed date, but it may be incomplete or out of date, and official sources take precedence. Bitcoin is volatile. A company that buys it could lose some or all of the money it puts in.
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