Tax and Accounting Changes to Consider in Spain in 2026

The 2026 financial year comes with several important tax and accounting developments affecting both SMEs and companies with higher volumes of activity in Spain. Some of these updates began to apply in 2025 and will have a direct impact on next year’s filings and formal obligations, while others will first be reflected in specific campaigns such as the 2026 Personal Income Tax return.

Below is an overview of the main changes that companies should consider when planning their year-end accounting and tax management.

New 24% corporate tax rate for small companies

One of the most significant developments is the introduction of a reduced 24% Corporate Income Tax rate for small-sized entities, applicable to financial years beginning on or after 1 January 2025. This reduced rate replaces the general 25% rate and represents a tax saving for companies meeting the turnover thresholds established in the Spanish Corporate Income Tax Law (LIS).

This change affects financial planning, instalment payments and year-end adjustments, making it essential for companies to review forecasts, regularisations and closing entries to ensure that the tax return correctly reflects the applicable rate.

Capitalisation reserve: increase to 20% and potential higher percentages

The capitalisation reserve, a tax incentive designed to strengthen a company’s solvency through an increase in equity, raises its deduction percentage from 15% to 20%.

To benefit from this reduction in the taxable base, companies must allocate the corresponding non-distributable reserve and maintain the increase in equity for five years.

Additionally, the framework allows for higher deduction percentages when a company increases its average workforce during the financial year, combining financial reinforcement with employment incentives.

This makes the capitalisation reserve especially useful for companies in expansion phases or those strengthening their financial structure.

Personal Income Tax (IRPF): mandatory filing for those applying for or receiving unemployment benefits

From the 2025 financial year (to be declared in the 2026 Personal Income Tax campaign), all individuals who have applied for or received unemployment benefits will be required to file a tax return, regardless of the amount received or whether they were previously exempt from filing.

This change significantly increases the number of taxpayers required to submit a return and calls for clear communication to avoid omissions or unintentional non-compliance.

Verifactu: voluntary enrolment in the SII system in 2026

Although the technical framework behind Verifactu began to be developed in 2025, its mandatory implementation has now been postponed to 2027, meaning that companies are not required to adopt the new system immediately.

At the same time, the legislation allows any business or professional to voluntarily join the Immediate Supply of Information (SII) system, a useful option for those wishing to advance in digital record-keeping or strengthen internal invoicing controls.

This voluntary option is requested through Form 036 by ticking the boxes for SII (143 and 532) and becomes effective from the following settlement period.

Once registered, the company must electronically submit invoicing records (issued and received) through the Spanish Tax Agency’s online platform.

Voluntary enrolment in SII may be particularly beneficial for companies seeking to align their transition to the broader Verifactu framework ahead of the 2027 deadlines, standardise internal processes, or further advance in digitalisation before the new requirements become mandatory.

Preparation and internal review ahead of the 2026 changes

The entry into force of these measures requires companies to review their tax and accounting policies to ensure that internal processes align with the new regulatory scenario.

Proper planning will help organisations approach the financial year with confidence and minimise risks arising from outdated procedures.

At LEIALTA, our tax and accounting team supports companies and professionals in understanding and applying these updates, helping them review closings, optimise incentives and adapt internal processes to comply with the 2026 regulatory framework with rigour and peace of mind.