Deducting a Home Office as an Autonomo: The 30 Percent Rule

If you work from home as an autonomo on Mallorca, you can deduct part of your housing costs, but only if you register it correctly and calculate it correctly. Since 2018, the Spanish tax authority has allowed electricity, water, gas, internet, and phone costs to be claimed proportionally as a business expense. The calculation uses a fixed formula that looks complicated at first glance but can be solved with a calculator in about a minute. This article walks through the formula, works out an example, and explains what owners can deduct on top of that, what applies to tenants, and which receipts Hacienda wants to see in an audit.

What the 30 Percent Rule Means

The 30 percent rule sets out how autonomos can deduct the suministros of their home when they work there: the deductible amount is the share of the work area in the total living space, multiplied by 30 percent, applied to electricity, water, gas, internet, and phone costs.

The legal basis is Article 11 of Ley 6/2017 of 24 October, which amended Article 30.2.5a of the Spanish income tax law (Ley 35/2006, LIRPF). The rule has applied since 1 January 2018 to all autonomos under the direct estimation method (estimacion directa).

Two requirements are worth knowing before you calculate anything:

1. The bills for electricity, water, or internet must be in your own name. If the contract is in your partner's name, the expense does not count as yours for tax purposes.
2. The space you use must be clearly defined, meaning a separate room or a clearly separated area. A desk in the middle of the living room does not meet the usual standard applied by the tax authority.

A Worked Example: 15 of 90 Square Meters

Say your home has 90 square meters, of which you use 15 square meters exclusively as an office. Here is how you calculate it:

1. Share of the work area: 15 of 90 square meters, so 16.7 percent of the home.
2. Deductible share of the suministros: 30 percent of 16.7 percent, so 5 percent.
3. With an assumed 2,400 euros in annual costs for electricity, water, and internet, that comes to 120 euros you can deduct as a business expense.

The 5 percent looks small at first, but it adds up over the tax years. More important than the absolute amount is documenting the calculation correctly in case Hacienda asks.

What Owners Can Deduct on Top

If you own your home, a second category of costs comes into play, and the 30 percent factor does not apply to it. Following the administrative practice of the Agencia Tributaria, you calculate these directly with the floor-area share, in our example 16.7 percent:

• Property tax (IBI)
• Comunidad de propietarios fees
• Building insurance (seguro de hogar)
• Depreciation (amortizacion) on the value of the building, excluding the land, usually applied at 3 percent per year

With an annual IBI of 400 euros, that would be 66.80 euros deductible in our example, with no extra 30 percent step. These four items are especially worthwhile if the home is yours and you are already carrying the full cost of these expenses anyway.

What Applies to Tenants

If you pay rent, you can claim the proportional rent itself as a business expense, again based on the ratio of square meters and without the 30 percent factor, because rent is not a suministro but a direct expense. For electricity, water, and internet, the same 30 percent formula applies as for owners, provided the contracts are in your own name.

IBI and comunidad fees are usually paid by the landlord, not by you as the tenant. These items are therefore usually missing from your own tax return, unless your lease explicitly passes them on to you.

Frequently Asked Questions

Do I have to notify Hacienda about the use before I can deduct anything? Yes. You enter the square meters and the degree of business use in Modelo 036, in the section on the place where you carry out your activity. Without this registration, there is no proof to support the later deduction.

What documents does Hacienda ask for in an audit? Bills in your own name for electricity, water, or internet, a floor plan or another record of the areas involved, and for tenants, the lease. Keep these documents for at least four years.

Can I deduct anything without a dedicated home office? Generally not, under the usual interpretation. The space you use must be clearly defined and recognizably assigned to your business activity; a desk in the kitchen does not meet that bar.

Conclusion

The 30 percent rule turns a home office into a small but cleanly documentable tax saving for autonomos. Three things matter most: registering it via Modelo 036, bills in your own name, and a space that is clearly separated from the rest of your home. Owners get extra value from IBI, comunidad fees, insurance, and depreciation, tenants from the proportional rent itself. Once you have set up the numbers cleanly, you only need to carry them forward in later years. For more on the ongoing obligations of being self-employed, see the guide Working as an Autonomo in Spain; the quarterly filings are explained in Autonomo Taxes in Spain: IVA and IRPF.