How to Claim Business Expenses as a Sole Trader in Ireland
If you're self-employed in Ireland, you can reduce your tax bill by claiming legitimate business expenses on your Form 11. But the rules are different from employees — particularly for motor expenses. This guide covers what you can claim, how to apportion mixed-use costs, and the mistakes that trigger Revenue disallowances.
Sole traders cannot use civil service mileage rates
This is the single most common mistake. The civil service mileage rates (€0.5182/km etc.) only apply to employees being reimbursed by their employer. If you're a sole trader, you claim actual motor expenses — fuel, insurance, motor tax, NCT, repairs, depreciation — apportioned for business use.
Employees
Civil service mileage rates (flat rate per km, by engine size and band). Employer reimburses, employee doesn't need receipts for fuel.
Sole traders
Actual motor running costs, apportioned by business use percentage. Must keep all receipts and a mileage log to establish the split.
What Sole Traders Can Claim
Any expense that is wholly and exclusively for business purposes is deductible. For mixed-use expenses (business and personal), you claim the business proportion only.
Motor Expenses
Apportioned by business use percentage:
- Fuel (petrol, diesel, electricity)
- Motor insurance
- Motor tax
- NCT fees
- Repairs and servicing
- Depreciation / wear & tear (capital allowances, Section 284 TCA 1997)
- Lease payments (business proportion)
- Tolls and parking (business trips only)
Phone & Broadband
Apportioned by business use percentage:
- Mobile phone bill (business portion)
- Broadband/internet (business portion)
- Landline (if used for business)
Office & Supplies
Usually 100% deductible if purely for business:
- Stationery and printing
- Computer equipment and software
- Postage and courier costs
- Business books and subscriptions
Professional & Other
Fully deductible business costs:
- Accountant and solicitor fees
- Business insurance (public liability, professional indemnity)
- Travel and accommodation for business
- Advertising and marketing
- Trade body subscriptions and CPD
How to Calculate the Business Proportion
For expenses with both business and personal use, you need to establish a reasonable business percentage. Revenue doesn't prescribe a formula — but they expect a consistent, documented method.
Motor expenses — worked example
You drive 20,000 km in the year. Your mileage log shows 14,000 km were for business. Business proportion: 14,000 ÷ 20,000 = 70%.
Total motor costs: €4,800 (fuel €2,400 + insurance €1,200 + tax €270 + NCT €55 + servicing €875)
Business deduction: €4,800 × 70% = €3,360
Phone bill — worked example
Your monthly phone bill is €60. Based on call logs and data usage, you estimate 70% business use.
Annual phone cost: €720
Business deduction: €720 × 70% = €504
Home office expenses — worked example
You use one room (15% of your home's floor area) as a dedicated office, working 5 days a week.
Annual heating + electricity: €2,800
Business deduction: €2,800 × 15% = €420
Note: If the room is also used personally (e.g., as a living room), the proportion should be further reduced to reflect the hours of business use.
The key principle: Whatever method you use, apply it consistently year to year and be able to explain it if Revenue asks. A mileage log for motor expenses and call records for phone costs are the strongest evidence.
Where to Claim: Form 11 via ROS
Sole traders report business expenses on their annual Form 11 income tax return, filed through ROS (Revenue Online Service). Expenses are entered in the self-employment income section and reduce your taxable profit.
Gather receipts
Collect all business expense receipts throughout the year
Calculate totals
Total each expense category, applying business proportions
File on ROS
Enter in the self-employment section of Form 11
Filing deadline: Mid-November for ROS filers (exact date varies by year), or end of October for paper filers. Late filing attracts interest and surcharges — up to 10% of the tax due.
Record-Keeping Requirements
Revenue can audit your tax return up to 4 years after filing (or 6 years if fraud is suspected). You must retain all supporting documents for at least 6 years.
What to keep
- All receipts and invoices
- Bank and credit card statements
- Mileage log (business vs personal trips)
- Phone/broadband bills with usage notes
- Calculation workings for apportioned expenses
Motor expenses specifically
- Fuel receipts (or credit card records)
- Insurance renewal/policy documents
- Motor tax payment confirmation
- Service and repair invoices
- Mileage log with business percentage calculation
The €3.20/Day Remote Working Allowance — Does It Apply?
No — this is for employees only
The €3.20 per day remote working allowance is a tax-free benefit that employers can pay to employees working from home. It does not apply to sole traders.
What you can do instead: Claim a proportion of your actual household running costs (heating, electricity, broadband) based on the floor area used for business and the time spent working. This often works out to more than €3.20/day — see the home office worked example above.
Common Mistakes That Trigger Disallowances
The most expensive mistake. Revenue will disallow the entire mileage claim if you've used flat rates instead of actual costs. You'll owe tax on the full amount plus interest.
Travel from your home to your regular place of business is commuting — even for sole traders. If you work from a rented office, the drive there is not a business expense.
No receipt = no deduction on audit. Revenue will disallow any expense you can't support with documentation, and you may face penalties for the original claim.
Claiming your entire phone bill or broadband as a business expense when you also use it personally. Revenue expects a reasonable apportionment — 100% business use is hard to justify for a personal mobile.
Without a log showing business vs personal kilometres, you have no basis for the business proportion. Revenue will likely reduce your claim to a fraction — or disallow it entirely.
Frequently Asked Questions
Related Resources
Free Calculator
Calculates civil service rates for employees. Sole traders: use this to understand the rates your employees are entitled to.
Try calculatorPolicy Template
If you have employees, use this to build a compliant travel expense policy.
View templateMileage Rates (Employees)
Civil service mileage rates for employees — not applicable to sole traders.
View ratesHave Employees Who Travel for Work?
If you're a sole trader with employees, Expense.ie automates their mileage and subsistence claims — correct progressive bands, automatic calculations, and ERR-ready exports. Your expense rules, applied consistently.
30-day money-back guarantee. No long contracts.