Bicycle mechanics: tracking workshop tools, components, and MTD compliance

A repair invoice can contain a chain, cassette, brake pads and an hour of labour. The customer sees one total. To understand the job properly, you need to see what you supplied, what it cost and what the labour earned.

Making Tax Digital for Income Tax brings a regular reporting rhythm to those records. For bicycle mechanics, the useful starting point is a clear distinction between customer components, reusable workshop tools and the everyday costs of keeping the repair business running.

That works whether you operate from a workshop, a mobile van or a combination of both.

Check MTD using income before component costs

MTD qualifying income generally combines gross sole-trader and property income before expenses. A component you supply at cost still normally forms part of your sales. The matching purchase reduces profit; it does not simply disappear from the turnover calculation.

For sole traders, more than £50,000 in 2024–25 gives an MTD start of 6 April 2026. More than £30,000 in 2025–26 gives 6 April 2027, and more than £20,000 in 2026–27 gives 6 April 2028. These dates are subject to exemptions in HMRC’s entry guidance.

A part-time mechanic may also have reportable rental income that brings the combined amount over a threshold. PAYE employment income does not count towards this test. Limited companies and partnerships require a separate assessment.

Worked example: parts supplied at cost

Suppose a customer pays £180 for a drivetrain repair, split as follows. The mechanic is not VAT registered; the figures are illustrative.

The business has £180 of income and £110 of component costs, leaving £70 before other expenses. It does not record only £70 of turnover because no margin was made on the parts.

If the customer independently buys their own components and pays you £70 solely for fitting, your sales are different. Record the actual commercial arrangement. The first example applies HMRC’s gross qualifying-income rule to an ordinary supply-and-fit repair.

Keep trade invoices connected to the components

Accounts with distributors such as Madison, Extra or ZyroFisher may combine several orders in one monthly payment. Keep the individual invoices and credit notes, not just the settlement total.

Your purchase records should make it possible to identify:

• Components installed on customer bikes.
• Stock retained for future repairs or retail sales.
• Tools and equipment kept in the workshop.
• Returns, supplier credits and warranty replacements.
• Items taken for your own bike or other private use.

For cash-basis accounts, allowable purchases normally follow payment. Traditional accounting may require stock and creditors adjustments. HMRC’s cash-basis guidance explains the payment approach.

A stock list is still useful even if your tax method follows payments. It can prevent ordering a second cassette you already hold, reveal slow-moving components and help you price repairs based on actual purchase costs.

Which workshop costs are normally allowable?

The business-purpose test in section 34 of the Income Tax (Trading and Other Income) Act 2005 applies. HMRC explains how it works.

Applying that test to a repair workshop, typical costs include chains, cables, bearings, brake pads, workshop degreasers, lubricants, cleaning products and other materials used in paid work. Workshop rent, appropriate insurance, utilities and repairs can also qualify to the extent they relate to the business.

Keep an itemised record when a purchase mixes business and personal components. Your own cycling hobby is not automatically part of your trade. A supplier receipt and a short note about which customer job used the item often resolve uncertainty later.

The cost of a repair you perform yourself also needs care: a sole trader cannot deduct a wage for their own time simply by assigning it an hourly value.

Treat specialist tools as equipment

Truing stands, bearing presses, torque wrenches, hydraulic bleed kits and workstands can last across many jobs. Equipment treatment depends on your accounting method.

Under cash basis, qualifying equipment bought outright normally counts as an expense when paid. Under traditional accounting, it generally receives tax relief through capital allowances. A depreciation entry in your accounts is not itself the tax deduction. See HMRC’s equipment guidance.

A practical purchasing record

If you buy a £650 truing stand and £85 of replacement cables on one invoice, keep the two items distinguishable. Under cash basis both may be deductible when paid, but separate records still help you understand tool investment, component spending and what you own.

Keep calibration or servicing costs for torque tools separately from purchases. For financed equipment, retain the contract so the arrangement can be treated correctly. A monthly direct debit does not explain whether you are hiring an item, repaying borrowing or purchasing it under a different agreement.

Make mobile van records useful

A mobile repair van may combine transport, storage and workspace. Keep invoices for leasing or purchase arrangements, racking, workstand mounting, insurance, servicing and running costs.

Where eligible, simplified mileage offers an alternative to actual vehicle expenses. For 2026–27, HMRC lists 55p per mile for the first 10,000 business miles and 25p thereafter for cars and goods vehicles. Conditions apply, including restrictions where the vehicle’s cost or capital allowances have already been claimed. See HMRC’s vehicle guidance.

Do not add fuel, insurance and repairs already covered by the mileage rate. If you use actual costs instead, establish any private-use share. Keep journey dates and purposes, including mobile callouts and parts collections. Ordinary commuting to a regular workshop is not automatically deductible.

For race-support work, record the business engagement and travel separately from any personal riding or leisure extension. A competition weekend can include both business and private spending.

Plan your quarterly review around completed jobs

MTD digital records and updates are governed by the Income Tax (Digital Obligations) Regulations 2026 and HMRC’s quarterly update direction.

Standard 2026–27 deadlines are 7 August 2026, 7 November 2026, 7 February 2027 and 7 May 2027. Each update is cumulative from 6 April. HMRC’s guidance explains the dates.

Before sending an update, reconcile cash and card takings, review outstanding customer payments, check supplier credits and make sure invoice imports have not duplicated bank payments. Keep any customer deposits connected to the relevant repair or custom build.

An annual return remains due: 31 January 2028 for 2026–27. Quarterly updates do not introduce quarterly income-tax payments. HMRC’s first-year relief for late quarterly updates does not remove the obligation to keep records and submit the required information.

Keep the accounts as organised as the workshop

Clear component and labour records help you judge whether each service is priced sensibly. Avona.app costs £15/month, with Avona AI helping categorise transactions for your review. Keep the itemised invoices alongside that process so mixed distributor purchases can be checked.

For managed support, Avona Concierge is managed by chartered accountants and starts from £60/month. Explore the Avona options and choose the support that fits your workshop or mobile round.