Multiple Business Activities in Your Limited Company: Splitting Income & Costs

Why Apportionment Matters for Your Company

If your limited company earns income from more than one business activity — say, consulting and property rental, or software development and training — HMRC expects you to treat each income stream correctly for tax purposes. Some activities may attract different tax treatments, VAT obligations, or allowable expense rules. Getting the split wrong can mean overpaying Corporation Tax or, worse, triggering an HMRC enquiry.

Common Scenarios Where This Arises

• Trading plus property income: A company that both trades and holds investment property must separate rental income from trading profits, as these are taxed differently within the Corporation Tax computation.
• Multiple trades: If your company genuinely runs two separate trades (for example, IT contracting and selling digital products), HMRC may treat these as distinct trade sources.
• Partially exempt VAT activities: If some supplies are VAT-exempt and others are taxable, you must apportion input VAT — you cannot reclaim VAT on costs that relate to exempt activities.
• Mixed personal and business use: Directors who use company assets partly for personal purposes must apportion costs accordingly, or face a benefit-in-kind charge.

Apportioning Income: The Basic Principle

Start by identifying each distinct income stream and recording it separately in your bookkeeping software from day one. Your company does not need to file separate tax returns for each activity — everything sits within a single Corporation Tax return (CT600) — but the underlying figures must be clearly supported. HMRC's starting point is that income is allocated to whichever activity generated it. If a single contract spans two activities, split the fee based on the actual work delivered, documented in writing.

Apportioning Expenses: Practical Methods

Expenses that relate wholly to one activity are straightforward — allocate them directly. The challenge is shared or overhead costs, such as rent, software subscriptions, accountancy fees, or a director's salary. HMRC accepts several reasonable apportionment methods, but the key is that your method must be consistent, justifiable, and applied throughout the accounting year. Common approaches include:

• Turnover-based apportionment: Split shared costs in proportion to the revenue each activity generates. If 70% of turnover comes from consulting and 30% from training, apply the same ratio to shared overheads.
• Time-based apportionment: If a director or employee splits their time between activities, log time spent and apportion salary costs accordingly. Keep timesheets as evidence.
• Headcount or floor-space: For office or premises costs, splitting by floor space used for each activity is widely accepted.

VAT Partial Exemption: A Separate Challenge

If your company makes both VAT-taxable and VAT-exempt supplies, you fall into the partial exemption rules. You must calculate the proportion of input VAT you can recover, using either the standard method (based on the ratio of taxable to total turnover) or a special method agreed with HMRC. This calculation must be done for each VAT return period and then reviewed with an annual adjustment. Getting this wrong is a frequent trigger for VAT compliance checks, so consider specialist advice if your exempt income is significant.

Record-Keeping Requirements

HMRC can enquire into your Corporation Tax return up to four years after the filing deadline for innocent errors, and up to 20 years in cases of deliberate non-compliance. Your apportionment methodology and supporting records must be retained throughout this window. Keep a written policy document explaining your chosen method, and ensure your bookkeeping reflects it consistently year on year.

When to Seek Professional Advice

Apportionment is not always straightforward, and the stakes are higher than many directors realise. If your company is growing into new activities, holds property, or has exempt VAT supplies, speak to a qualified accountant before your next accounting period begins. Setting up the right structure from the start is far cheaper than correcting it later under HMRC scrutiny.