Home office, car and phone: how deductions really work

Key rules

• Home utilities: Working from home, you can deduct 30% of the part of your utility bills matching the share of the home used for the activity.
• Car: A car is deductible only if used exclusively for your activity, apart from set exceptions such as taxis and delivery vehicles.
• Phone: Only the provable work share of a mixed phone or internet line is deductible.
• Travel: Travel meals and lodging need an invoice and electronic payment, and must be away from your home and usual workplace.

Home utilities: 30% of the share you use

If you work from the home where you live, you can deduct 30% of the part of your utility bills that matches the share of the home used for the activity. Say 10% of the surface is your office. You then deduct 30% of 10% of the bills.

This covers water, electricity, gas, phone and internet. It applies whether you own or rent.

To claim it:

• The space must be set aside for the activity.
• The bills must be in your name.
• You record the use in your books.

Property tax and mortgage interest are limited to the same proportion.

This applies to autónomos using direct estimation.

Car: only if it is used only for work

A vehicle is deductible for income tax only if you use it exclusively for the activity. Mixed private and business use is not accepted.

There are exceptions that can deduct fully:

• sales representatives and commercial agents
• delivery vehicles
• taxis
• driving schools
• vehicles for hire, or for transporting goods and passengers

A vehicle used for the activity may also qualify for depreciation.

For VAT, business use is presumed to be 50%. So you can recover up to 50% of the VAT on vehicle costs, unless you prove a higher use. Proving that use is your job, so keep records. Reform of vehicle rules has been discussed, so check the current position with the tax agency (AEAT) before you claim.

Phone and internet: only the work share

A line used only for the business is fully deductible. On a personal or mixed line, only the part you can show is for the activity counts. At home, the 30% rule above applies to these bills. Invoices must be in your name.

In practice a reasonable share is usually accepted. A separate business line avoids disputes.

Travel meals and lodging

Meals and lodging while travelling for the activity follow the same daily limits as employee per diems. The expense must be:

• away from your home and your usual place of work
• paid by card or other electronic means
• backed by an invoice

Daily limits for 2025 were 26.67 euros in Spain and 48.08 euros abroad without an overnight stay. Other limits apply when you stay overnight. Check the current figures in the income tax regulation before you deduct.

The checklist and FAQ below cover the steps and common questions.

Checklist

• Confirm that the vehicle is used only for your activity before you deduct it, or that you fall into an exception such as taxi, delivery or driving school.

• Keep proof of business use of the vehicle, since proving it is your job if the tax agency asks.

• Check that each travel meal or lodging expense was away from your home and your usual place of work.

• Pay travel expenses by card or electronic means and keep the invoice.

• Compare your daily meal and lodging amounts with the current limits in the income tax regulation before you deduct them.

Frequently asked questions

Can I deduct my car if I also use it privately?

No, a car used for both work and private life is not deductible for income tax, because the vehicle must be used only for the activity. Exceptions are sales representatives, delivery vehicles, taxis, driving schools and vehicles for hire or transport. For VAT, up to 50% of the input VAT can be recovered unless you prove a higher business use.

Can I deduct a mobile line that I also use personally?

Yes, you can deduct a mixed phone line, but only the part you can show you use for the activity. A separate business line is fully deductible and avoids disputes. Keep invoices in your own name.

What expenses count for travel per diems?

Meals and lodging while travelling for the activity count, if the expense is away from your home and your usual place of work.