Office, Stationery & Software

What Counts as Office Expenses?

HMRC's "Office costs" category on the SA103 Self Assessment form covers a wide range of everyday business spending. The key test is that the expense must be wholly and exclusively for business purposes — or, if shared with personal use, only the business proportion can be claimed.

Here are the main items you can claim:

• Stationery and printing: Paper, pens, ink cartridges, notebooks, folders, sticky notes — all fully claimable if used for business.
• Postage and packaging: Stamps, courier fees (Royal Mail, DPD, etc.), padded envelopes, and packaging materials for sending goods or documents.
• Software subscriptions: Adobe Creative Cloud, Microsoft 365, Slack, Trello, Xero, accounting software — any tool you pay for monthly or annually for business use.
• Phone bills: The business proportion of your mobile or landline. If you estimate 60% of calls are for business, claim 60% of the bill.
• Internet: The business proportion of your broadband. If you work from home, a common split is 25-50% depending on usage.
• Computer equipment: Laptops, monitors, keyboards, mice, printers, external drives. Items under roughly £1,000 that will last less than 2 years are usually treated as expenses; bigger items may need to go through capital allowances.
• Domain names and hosting: Website hosting fees, domain registration, SSL certificates, and email hosting.

What You CANNOT Claim

It's just as important to know what's not allowable:

• Personal phone calls: Only the business proportion of a shared phone bill is claimable. If you have a separate business phone, the entire bill can be claimed.
• Full broadband bill: Unless your broadband is used 100% for business (rare if you live in the property), you can only claim the business proportion.
• Personal software: Netflix, Spotify, gaming subscriptions, personal cloud storage — these are personal and not claimable even if you occasionally use them during work hours.
• Capital items (over threshold): High-value items like an expensive camera or a £3,000 MacBook Pro may need to be claimed as capital allowances rather than expenses, depending on your accounting method.

How to Calculate Your Phone and Broadband Split

HMRC doesn't prescribe an exact method for splitting shared bills, but they expect your estimate to be reasonable and evidenced. Here are two approaches:

Method 1: Usage-based estimate

Review your phone bill for a typical month. Count the business calls versus personal calls. If 70% of your calls and data usage is business-related, claim 70% of the monthly bill. Keep a record of how you calculated this.

Method 2: Time-based estimate

If your broadband is shared between work and personal use, estimate how many hours per week you use it for business versus personal. For example, if you work 40 hours a week from home and use the internet for personal use for 20 hours, your business proportion is roughly 67%.

Tip: Whichever method you choose, stick with it consistently and keep a note of your reasoning. HMRC is unlikely to challenge a reasonable estimate, but they will challenge one that looks inflated.

Computer Equipment: Expenses vs Capital Allowances

There's a common question about whether computer equipment should be claimed as an expense or a capital allowance. The answer depends on two things: the cost and your accounting method.

If you use cash basis accounting (the default for most sole traders earning under £150,000), you can claim most equipment as an expense in the year you buy it, regardless of the price. The main exception is cars.

If you use accruals accounting, items expected to last more than 2 years and costing more than roughly £1,000 are usually claimed through capital allowances (Annual Investment Allowance) which still gives you 100% relief in year one.

If a computer is used partly for personal and partly for business, you can only claim the business proportion. For example, a £1,000 laptop used 80% for business = £800 claimable.