When a Spanish SL makes sense: signals and costs

We already wrote about the 25% myth and the numeric comparison lives in the tool. This guide is about the other half: what it costs to LIVE with an SL, and the non-tax signals that mark the moment. The bar is concrete: the structural cost of a live SL runs roughly 8,000-10,000 euros a year before the first euro of tax saving, and the retained profit has to clear it.

What it costs to keep alive (even billing nothing)

A live SL costs money every month, profit or loss:

Cost	Typical figure	Note
Accountant with commercial bookkeeping	150-300 a month	The usual range for a small services SL
Corporate-partner Social Security quota	About 448 a month	The 2026 floor applies profit or loss
Corporate tax return and annual accounts at the Mercantile Registry	Part of the accountant’s yearly cycle	Every year, even with no activity
Incorporation: notary, registry, 3,000 share capital	One-off	The capital can be paid in and then used: not lost, but parked at the start

Round sum: roughly 8,000-10,000 a year of structural cost before the first euro of tax saving. That is the bar the retained profit has to clear. The quota floor is the one figure above with an official 2026 value, checked 2026-08-22 against Wolters Kluwer’s 2026 quota summary; the accountant range and the round sum are our house estimates.

The five signals it is time

1. Sustained profit you do NOT need to take out in full to live: the condition that makes the 15-25% deferral work.
2. Contracts where limited liability genuinely matters: large projects, claim exposure, insurers that require a company.
3. Corporate clients or public tenders that demand a company invoice.
4. Partners: splitting percentages of a sole-trader activity is a workaround, splitting shares is a contract.
5. A real intention to sell the business one day: a company transfers, a personal client book barely does.

The three signals it is not

If your profit hovers at or below 60,000 and you take all of it home, the SL usually means paying for structure to be taxed about the same. If your motivation is a sentence that starts with “someone told me that”, go back to the comparison with your own numbers. And if your business is you and only you selling your hours with no serious asset exposure, limited liability protects less than it sounds: banks will ask for your personal guarantee anyway, and professional liability is better covered by insurance.

If you make the move

Do it in January rather than November (a clean fiscal year, no split exercise), with the accountant hired BEFORE incorporating, and with the client migration planned: new invoices with the new details, contracts renewed in the company’s name, and your corporate-partner registration coordinated with closing or amending your previous one. The expensive mistake is incorporating first and asking questions after.