Direct Estimation vs. Modules: Which Personal Income Tax Regime Suits Your Business

Every self-employed professional who registers with the Spanish Tax Agency (Hacienda) eventually runs into the same question: direct estimation or modules? The answer determines how personal income tax (IRPF) is calculated, which formal obligations apply, and, in many cases, how much is paid to the Tax Agency each quarter. It isn’t always a free choice — it depends on the type of activity and certain revenue thresholds — but understanding both regimes well makes it possible to get the decision right from day one or, for those already registered, to know when it’s worth switching.

Direct Estimation: Taxed on Actual Profit

Under direct estimation, personal income tax is calculated on the business’s actual profit: income minus properly justified deductible expenses. This is the general regime and the only one available to the vast majority of professionals (lawyers, consultants, designers, doctors, IT specialists…), who are excluded from modules because of the type of activity they carry out, regardless of their turnover.

There are two variants within direct estimation. The normal variant, mandatory above a certain annual turnover, requires bookkeeping in line with the Commercial Code (general ledger, balance sheet, annual accounts) for commercial activities, or the income, expense, capital-goods and funds-provision registers for professional activities. The simplified variant, which applies below that turnover threshold unless expressly waived, follows the same income-minus-expenses approach but with lighter accounting requirements, and allows a fixed percentage of net income to be deducted for hard-to-justify expenses.

The advantage of direct estimation is that it reflects what the business actually earns: a bad quarter means less income tax. The downside is the administrative load — every invoice, expense and receipt has to be kept and recorded — and that in very good years the tax bill can end up higher than under modules.

Objective Estimation (Modules): Taxed on Signs, Indices and Modules

The modules regime works out net income by applying objective parameters of the activity — number of employees, contracted electrical power, floor space of the premises, number of vehicles, among others depending on the business category — to tables the Tax Agency publishes every year, regardless of the profit actually earned. In other words, the amount due stays the same whether that quarter’s turnover came in above or below expectations, within certain margins.

Only the business activities expressly listed by the Tax Agency can opt for modules (professional activities cannot): retail trade, hospitality, freight and passenger transport, hairdressers and beauty salons, repair shops, some agricultural, livestock and forestry activities, and little else. Beyond falling under the right category, annual turnover and purchase limits (goods and services, excluding capital assets) must be respected to stay in the regime; these limits are set — and have been extended year after year — by ministerial order, so it’s always worth checking the exact figure in force for the current tax year before deciding, since it can change from one year to the next. There is also a specific limit on income from other businesses or professionals required to issue invoices (B2B transactions), which tends to be tighter than the general turnover limit.

The advantage of modules is simplicity — there’s no need to track every single expense — and, for businesses with high margins and low real costs, it can end up cheaper than direct estimation. The risk cuts the other way too: if business slows down, tax is still due based on the module, not on what was actually earned.

When It Makes Sense to Switch Regimes

Switching from direct estimation to modules (or the other way around) is done through the corresponding census declaration (Form 036/037), normally filed in December of the year before it is to take effect, or when first registering for the activity. It’s worth reviewing the situation every year, especially in these cases: when turnover is approaching the modules thresholds (switching to direct estimation can become mandatory rather than optional); when the business starts incurring high, real expenses that can’t be deducted under modules; when extra staff are hired or the premises change, altering the module’s parameters; or when the business starts billing mostly other companies, which can trigger the specific B2B limit and force an exit from the regime.

Once modules has been waived, keep in mind that going back isn’t immediate: there’s a minimum period that must be spent under direct estimation before returning to modules, so the decision should be based on projections covering at least two tax years, not just the current quarter.

At Zythos Business we help self-employed professionals and small businesses with exactly this kind of decision: we look at the activity, actual margins and the business’s likely path forward to work out which personal income tax regime fits best at each stage, and we handle the census declaration and all the tax obligations that come with the change, so the choice is based on numbers rather than guesswork.