The monthly close: five checks when your company holds bitcoin

A short routine that keeps the wallet, the ledger and your accountant in step.

Welcome to the first issue of the IoT Financial newsletter: one treasury lesson a week for small companies in the UK and the US that hold, or are thinking about holding, bitcoin.

Each issue has four parts: a lesson, an update from an official source, a worked example and a link to a tool on the site.

This week's lesson: the monthly close

Most of the risk in holding bitcoin as a company is not dramatic. It is small gaps that build up: a fee nobody recorded, a price taken from a different site each month, a transfer that sits on the wrong side of the month end. A short monthly close stops those gaps from turning into a long clean-up at year end.

Here are five checks to run each month.

1. Match the wallet to the ledger. Compare the units of bitcoin the company actually holds (from the wallet software, or the custodian or broker statement) with the units in your accounting records. They should agree exactly. If they do not, find the reason before you close the month.

2. Use one price source, at one time. Pick a single price source and a fixed time of day for valuing the holding (for example, a named exchange or index at 23:59 UK time on the last day of the month). Write the choice down and use it every month. Switching sources makes the numbers hard to compare and hard to explain.

3. Account for fees. Network fees on transfers, and trading or custody fees, reduce what the company holds. Record each one with its date and value, and agree with your accountant how the company treats them.

4. Respect the cut-off. A transfer started on the last day of the month may confirm on the first day of the next. Decide which date counts (for example, the date the transaction confirms on the network) and apply that rule the same way every month.

5. Keep an evidence file. For each month, save the wallet or statement balance with a date and time, the price used and its source, the list of transactions and fees, and a note of who checked it and when. If a second person reviews the close, record that too. This is what your accountant will ask for at year end, and it is far easier to gather monthly than all at once.

None of this needs special software. A spreadsheet and a shared folder are enough for most small companies, as long as the routine is the same each month.

UK update: HMRC Cryptoassets Manual

We checked the "updates to this manual" log for HMRC's Cryptoassets Manual on 25 October 2026. The most recent change to the business sections (CRYPTO40000 onwards) is dated 10 November 2025, when the contents page added CRYPTO49000 on the Cryptoasset Reporting Framework. The only later entry, on 28 November 2025, concerns Inheritance Tax for individuals. So nothing new for companies this month.

One page worth knowing for the monthly close is CRYPTO40100. It says a company's profits must be worked out in pounds sterling, using an appropriate rate at the time of each transaction, with reasonable care, a consistent method, and a record of that method. Checks 2 and 5 above are one practical way to keep that record. Check with your adviser how it applies to your company.

• HMRC Cryptoassets Manual: updates
• HMRC CRYPTO40100: conversion to sterling and accountancy

Worked example (UK, illustrative)

Example Studio Ltd is an invented company and all figures are examples.

At the end of the month, Example Studio Ltd's ledger shows slightly more bitcoin than its wallet does. The director running the close looks at the month's transactions and finds the reason: the company moved its holding from one multisig wallet to a new one during the month, and the network fee for that transfer (an example £12 at the time of the transaction) was never entered.

The director:

1. Records the fee with its date, the units, its sterling value at the time (using the company's usual price source) and the transaction reference.
2. Re-runs check 1, and the wallet and ledger now agree.
3. Saves the wallet balance, the price used and a note of the fix to the month's evidence file.
4. Flags the item for the accountant, who confirms how the company treats network fees, so the same treatment is used every time.

The amount is small. The point is that it was found and explained within the month, not reconstructed months later.

Use this

If you downloaded our policy template, section 7 (Accounting and records) has paired UK and US clauses on what to record for each transaction. The policy guide lists what that section covers, and its UK and US points to check explain the record keeping each market expects:

• Policy guide: what a policy should cover
• Policy guide: US and UK points to check

If there is a topic you would like covered, email hello@iotfinancial.net.