Which expenses are deductible for self-employed workers

A deductible expense for a self-employed worker is generally an expense connected to the economic activity, properly supported, and recorded in the required accounts or books. The specific rule depends on the tax, the type of expense, and the professional's circumstances.

Quick summary

For an expense to be considered deductible, it normally needs to meet these conditions:

1. Be related to the activity.
2. Be justified with an invoice or valid document.
3. Be recorded in the relevant book or accounts.
4. Be allocated to the correct period.

Paying from a business account helps demonstrate the transaction, but payment by itself does not make an expense deductible.

Deducting an expense for income tax is not the same as deducting its VAT

Consider two questions separately:

• Personal income tax: whether the expense can reduce the net income from the activity.
• VAT: whether input VAT can be deducted from output VAT.

An expense can be treated differently under each tax. For example, having an invoice and recording an expense does not by itself guarantee that all its VAT is deductible. Its use in the activity and specific VAT restrictions also matter.

Common examples

These examples may be deductible when they meet the applicable requirements:

• Professional tools, licences, and software.
• Management, advisory, accounting, or legal services connected to the activity.
• Materials, inventory, and other supplies needed for the work.
• Business premises rent, utilities, and professional services.
• Social Security contributions and certain insurance connected to the activity.
• Training directly related to the work performed.
• Travel, subsistence, or vehicles when their specific conditions are met.

Inclusion in this list does not confirm that a specific expense is deductible. Vehicles, a partly business-use home, subsistence, travel, and mixed-use expenses need particular care.

Which records to keep

• The complete invoice or accepted supporting document for the transaction.
• Evidence of payment when it helps demonstrate that the transaction was genuine.
• The contract, order, or service explanation when the business purpose is not evident.
• The entry in the expenses book or accounts.
• Additional records required for travel, subsistence, capital goods, or special transactions.

Check that the invoice correctly identifies the supplier and recipient, describes the transaction, and shows the relevant dates, taxable bases, and taxes. Ask for a correction if the tax details are wrong.

Common mistakes

Keeping only the bank transaction

The transaction helps prove payment, but it does not always replace the invoice.

Mixing personal and professional expenses

Separating expenses avoids doubts and makes accounting review easier.

Automatically deducting every expense with an invoice

An invoice records information about the transaction, but you must also be able to explain how the expense relates to income or the business activity.

Applying the same rule to income tax and VAT

Each tax has its own rules. Review the expense and input VAT separately before recording them.

Uploading documents late

Uploading documents near close can create rush and errors.

Checklist before sending an expense to your adviser

1. Confirm that the expense belongs to the activity and is not personal.
2. Check that the document contains the correct tax details.
3. Add a note when the business purpose is not evident.
4. Separate personal amounts when there is mixed use.
5. Upload the document in the correct period.
6. Keep the original for the applicable statutory period.

How Numonis helps

Numonis lets you centralize invoices, receipts, and supporting documents so your accountant can review them before close and request information if something is missing. See what to upload and when and how to upload documents.

If you want a managed accounting and tax service, learn how Numonis works with SMEs and self-employed workers.

Frequently asked questions

Is a receipt enough to deduct an expense?

It depends on the tax, expense, and information on the receipt. A simplified invoice may need additional details to support a VAT deduction. Ask for a complete invoice when required.

Can I deduct a purchase paid from my personal account?

The payment method does not decide deductibility by itself. However, mixing personal and business payments makes the audit trail harder to follow. Keep the invoice, proof of payment, and explanation of its connection to the activity.

Can I deduct all vehicle expenses?

Not automatically. Business use and the rules for vehicles are specific and may differ between personal income tax and VAT. Ask about your circumstances before claiming a deduction.

Official sources

• Spanish Tax Agency requirements for a deductible expense
• 2025 practical income tax manual: deductible business expenses
• Invoice types and the requirements for deducting VAT

Notice

This content is informational and describes general rules. It does not replace personalized tax advice or confirm that a specific expense is deductible.