Sole trader or limited company in Spain: when corporate tax really pays off

Sole trader or limited company: the calculation that decides it, and almost nobody does it

A high-earning sole trader in Spain gets the usual advice from his accountant: set up a limited company (SL), pay Corporate Income Tax and save on personal income tax. He resists. He has already been the manager of an SL and remembers invoices, cash registers, inventories, delivery notes and an accountant on payroll. "I'd rather stay a sole trader even if I have to pay more taxes," he argues. The question is not rhetorical: is it madness?

The short answer is no. The long one depends on where the money is when the year ends.

Where the tax savings of an SL come from

The sole trader's profit is taxed under personal income tax (IRPF) with marginal rates that, depending on the region, reach 45-47%. In a limited company, profit kept inside pays Corporate Income Tax, around 23-25% for SMEs, less for newly created companies in their first years.

That's the hook. And that's the trap: the savings only exist with the money you don't take out. What you withdraw as salary pays IRPF just as before. What you withdraw as a dividend is taxed again, under the savings base. If you need the entire profit to live on, the advantage narrows until it almost disappears.

The 75% rule the tax authority watches

In professional companies —lawyers, consultants, doctors, architects— the Companies Act sets a safe harbour: if the shareholder is paid at least 75% of the profit before the company pays tax on it, the tax agency (Hacienda) accepts the arrangement. In commercial activities there is no fixed percentage, but the general market-value rule applies. And in practice, inspections are being peine, penalties included, when the company has no resources of its own and all the work is done by the shareholder.

Translated: a single-member SL without structure is, in the eyes of the tax agency, a sole trader with extra paperwork. The savings get eaten up by the assessment.

Rented premises and employees: when an SL does make sense

The picture changes if there is an intention to hire. With a couple of employees and a rented warehouse, the activity is genuinely business-like. The tax authority has less room to argue that the profit comes from the owner's personal work, and retained profit is taxed without so much dispute.

Then the other advantage appears, the one that doesn't show up in the spreadsheet: limited liability. A dismissal that ends up in court, a workplace accident, a problem at the premises. As a sole trader you answer with your personal assets; with an SL, in principle only with the company's, unless you have signed personal guarantees. And there's an extra that is often forgotten: grants and public tenders usually require a corporate structure.

The cost that doesn't appear in the calculator

Bureaucracy is not an abstract nuisance. It's bookkeeping, inventory, cash, delivery notes, reconciling every transaction and coordinating with the accountancy firm. In sectors with heavy physical traffic, automating it is a pipe dream. Some claim that with AI tools it can be dealt with in a few afternoons; those who have lived through it know the problem isn't the software, it's the volume of human decisions nobody automates for you.

Add to that the risk of an inspection of the single-member company, which concentrates the tax authority's attention. And the internal toll: responsibilities spread around, friction with partners or employees, time stolen from the real business.

The question that remains open

The full calculation, with a reasonable salary, dividend, self-employed social security contribution and accountancy costs, gives a difference that surprises those who only look at the Corporate Income Tax rate. But the final number depends on how much you need to take out each month and how much your time is worth. There, no accountant can help you.