Phone and Internet Expenses: What You Can Claim

In today's interconnected business world, phone and internet services are not just conveniences — they're necessities. But knowing what you can legitimately claim as a business expense can be a maze of HMRC rules and regulations. This comprehensive guide will walk you through the intricacies of claiming phone, internet, and other digital expenses for your UK business in the 2026/27 tax year, ensuring you maximise your tax efficiency while remaining compliant.

The 'Wholly and Exclusively' Rule

At the heart of HMRC's expense rules lies the principle of "wholly and exclusively". This means that for an expense to be allowable for tax purposes, it must have been incurred solely for the purposes of your trade, profession, or vocation. If an expense has a dual purpose — meaning it serves both a business and a personal need — then generally, the personal element cannot be claimed.

Phone Expenses for Sole Traders

For sole traders, mobile phone expenses are a common area where business and personal use often overlap. Understanding how to correctly claim these costs is vital for compliance and maximising your allowable expenses.

Business-Only Phone

If you have a mobile phone contract that is used 100% exclusively for business purposes, then the entire cost of the contract, including line rental and calls, is an allowable expense. This is the simplest scenario for claiming, as there's no need for apportionment.

Mixed-Use Phone

More commonly, sole traders use a single mobile phone for both business and personal calls. In this situation, you can only claim the business proportion of the costs. HMRC expects a "fair and reasonable" method of apportionment. Common methods include:

• Call Log: Keeping a log of business calls (duration, recipient, purpose) and calculating the percentage of business use based on call time or cost.
• Time-Based Estimate: Estimating the percentage of time the phone is used for business activities versus personal use.
• Data Usage: If data is a significant component, estimating the business proportion of data usage.

While you don't need to log every single call, you should have a clear methodology and sufficient evidence to support your apportionment if HMRC were to inquire [1].

Example: Mixed-Use Mobile Phone Expense Calculation (2026/27)

_This example illustrates how a sole trader might calculate their deductible mobile phone expenses._

Phone Expenses for Limited Companies and Employees

The rules for limited companies differ significantly from those for sole traders, particularly concerning Benefit in Kind (BiK) implications for employees and directors.

Company-Provided Phone (Contract in Company Name)

This is often the most tax-efficient way for limited companies to handle mobile phone expenses. If the company provides an employee (including a director) with a mobile phone and the contract is in the company's name, the following applies:

• The company can claim 100% of the contract cost as an allowable business expense, reducing its Corporation Tax liability.
• There is no Benefit in Kind (BiK) charge for the employee, even if there is incidental personal use, provided it is one phone per employee [2]. This means the employee does not pay personal income tax or National Insurance on the benefit.

Employee's Personal Phone Used for Business

If an employee uses their personal mobile phone for business calls, the company can reimburse them for the actual cost of business calls. However, claiming a proportion of the line rental or contract cost is generally not allowable due to the "duality of purpose" rule — the employee would have incurred the line rental cost regardless of business use [2].

If the company pays the employee's personal mobile phone contract directly, this will almost certainly trigger a BiK charge. The company would pay Class 1A National Insurance Contributions on the value of the benefit (currently 13.8% for 2026/27) [3], and the employee would incur a personal income tax liability on the value of the benefit.

Comparison: Personal vs. Company Phone Contracts (2026/27)

_This table outlines the tax implications for different mobile phone arrangements._

Internet Expenses

Just like phone expenses, internet costs can be claimed, but the rules vary depending on whether you have a dedicated business connection or use your home broadband for work.

Separate Business Broadband

If you have a broadband contract specifically for your business premises or a dedicated line for business use at home, then 100% of the cost is claimable as an allowable expense. This is the clearest-cut scenario and avoids any apportionment complexities.

Home Broadband (Mixed-Use)

Many self-employed individuals and limited company directors use their existing home broadband for business purposes. In this case, you can only claim the business proportion of the cost. You cannot claim the entire bill, as there is a clear personal element. HMRC requires a "fair and reasonable" method of apportionment [4].

Here's a step-by-step guide to calculating your home broadband business proportion:

1. Determine Total Monthly Cost: Find your total monthly broadband bill. For example, £35 per month.
2. Estimate Business Usage: Consider factors like hours spent on business activities online, number of business users vs. personal users, or dedicated business tasks (e.g., website management, online meetings). Let's say you estimate 50% business use.
3. Calculate Monthly Business Portion: Multiply the total monthly cost by your estimated business usage percentage. (£35 * 50% = £17.50).
4. Calculate Annual Business Portion: Multiply the monthly business portion by 12. (£17.50 * 12 = £210).
5. Keep Records: Document your methodology and any evidence supporting your estimated business usage.

It's important to be consistent with your chosen method and be prepared to justify it if asked by HMRC.

Software Subscriptions

In the digital age, software subscriptions are an increasingly common business expense. Fortunately, these are generally straightforward to claim:

• If a software subscription is used wholly and exclusively for business purposes, then 100% of the cost is an allowable expense.
• Examples include accounting software (e.g., QuickBooks, Xero, FreeAgent), project management tools (e.g., Asana, Trello), customer relationship management (CRM) systems, industry-specific software, and professional design tools.
• Even if you access the software on a device used for personal reasons, the subscription itself is typically 100% claimable if its function is purely business-related.

HMRC's Approach to Mixed-Use Digital Expenses

HMRC understands that in modern business, a clear-cut separation between personal and business use of digital services isn't always possible. Their primary concern is that claims are reasonable, justifiable, and not an attempt to claim for significant personal expenditure.

• Reasonableness: Your apportionment method should be logical and reflect actual usage. Wildly optimistic percentages are likely to be challenged.
• Justification: Be prepared to explain how you arrived at your business-use percentage. This could involve call logs, time tracking, or a simple, consistent estimate.
• Record-Keeping: Maintain clear records of your expenses and your apportionment calculations. This evidence is invaluable if HMRC opens an inquiry.

While HMRC doesn't provide fixed percentages for mixed-use items, they expect taxpayers to apply common sense and honesty. The goal is to claim only the portion that genuinely relates to your business activities.

Pros and Cons of Different Approaches

The optimal way to handle phone and internet expenses can depend on your business structure (sole trader vs. limited company) and your usage patterns. Here's a comparison of the pros and cons of different approaches.

Sole Trader vs. Limited Company for Phone/Internet Expenses

_This table highlights the key differences in claiming phone and internet expenses based on business structure._

Conclusion

Navigating the rules for claiming phone and internet expenses in the UK requires careful attention to detail, especially when dealing with mixed business and personal use. The "wholly and exclusively" rule and diligent record-keeping are paramount.

By understanding the nuances of mixed-use apportionment, the benefits of separate business contracts, and the BiK implications for employees, you can ensure your claims are accurate, justifiable, and maximise your tax efficiency for the 2026/27 tax year. Always aim for transparency and be prepared to demonstrate how your expenses directly contribute to your business operations.

References

• [1] ByteStart: [Phone and internet expenses for sole traders: HMRC rules and allowances](https://www.bytestart.co.uk/self-employed-accounts/phone-internet-phone-expenses-sole-traders/)
• [2] IT Contracting: [Claiming phone, mobile and broadband expenses via your limited company](https://www.itcontracting.com/phone-broadband-expenses/)
• [3] GOV.UK: [National Insurance rates and categories: Contribution rates](https://www.gov.uk/national-insurance-rates-letters)
• [4] GOV.UK: [Expenses if you're self-employed](https://www.gov.uk/expenses-if-youre-self-employed)