Part-time contracts in Spain

The short answer

A Spanish part-time contract is not an ordinary contract with fewer hours. Article 12 of the Workers' Statute puts it in a regime of its own, and the rules of that regime are more restrictive than almost anybody expects: it forbids overtime, it requires the hours in writing, it requires the working day to be recorded daily and the summaries kept for four years³, and it presumes the contract is full-time whenever either of those documentation duties is missed.

What part-time means, and who the comparison is with

No number defines it. Paragraph 1 says the contract is part-time «where the provision of services has been agreed for a number of hours a day, a week, a month or a year that is lower than the working time of a comparable full-time worker»². Thirty-nine hours against a 40-hour week is part-time too, with everything that follows.

The interesting part is the second paragraph, because it gives not a figure but a three-step cascade for deciding who the comparison is with:

The forty hours everybody takes for granted are the third step, and they come from art. 34.1⁵, not from art. 12. If your workplace has a comparable worker on a different week, the reference is that person's, and that moves the art. 12.4.c) ceiling explained below.

You cannot do overtime

This is the rule most often broken without anybody noticing, because it cuts against intuition. Letter c) of paragraph 4 says that «part-time workers may not do overtime, except in the cases referred to in article 35.3»³, which is force majeure.

What the law does allow are complementary hours, and they are not the same thing in two ways that matter. First, they need a specific written pact and a contract of at least ten hours a week⁴. Second, letter i) of paragraph 5 requires them to be paid «as ordinary hours», so they carry none of the premium a reader expects from an extra hour. The difference between the two is not vocabulary: it is the price of the hour.

Three caps, and not always the same one binds

The cap that circulates is 30 %. There are three, and which binds depends on your hours:

The first two ADD, because the second paragraph of letter g) says voluntary hours «shall not count towards the percentages of pacted complementary hours established in letter c)»⁴. And the third overrides both above a certain level of contracted hours: with a 40-hour full-time week and the statutory caps, the crossover sits at 27.59 contracted hours. The complementary-hours calculator resolves it with your real hours and says which of the three limits you are under.

The two presumptions of full-time work

Paragraph 4 contains two rules that turn a documentary slip into a legal presumption, and they are independent of each other:

Both allow evidence to the contrary, so they are not automatic, but they invert who has to prove what. And the recording duty has a tail: working time must be totalled monthly, a copy of the summary given to you with your payslip, and those summaries kept «for a minimum period of four years»³.

Moving to part-time is always voluntary

Letter e) of paragraph 4 is one of the few working conditions article 41 does not reach. Conversion from full-time to part-time and back «shall always be voluntary for the worker and may not be imposed unilaterally or as a consequence of a substantial change of working conditions under article 41.1.a)», and the worker «may not be dismissed or suffer any other kind of penalty or detriment for refusing that conversion»³.

The same letter also requires the employer to publicise vacancies so that voluntary conversions or an increase in hours can be requested, and to refuse such requests in writing and with reasons.

Refusing, and getting out of the pact

There are two rules about refusing rather than one, and the second is broader than the first.

Letter f) of paragraph 5 says that where any of the preceding letters is breached, «the worker's refusal to work the complementary hours, even though they have been pacted, shall not constitute punishable conduct»⁴. So with the pact signed, if you are given one day's notice instead of three, or asked for more hours than fit, refusing is protected.

Letter g) goes further for voluntary hours. It says «the worker's refusal to work these hours shall not constitute punishable conduct», with no condition on any breach at all⁴. Declining an offer of voluntary hours is never punishable, even where the offer is perfectly lawful.

And there is a symmetry worth seeing together, because the collective agreement has two powers pointing in opposite directions in consecutive letters:

The Statute says «a minimum notice of three days» and does not say whether they are calendar or working days, so neither does this page.

To get out of the pact, letter e) requires three things at once: fifteen days' notice, a full year since it was signed, and one of three closed grounds, which are the family responsibilities of art. 37.6, training needs with proven timetable incompatibility, or incompatibility with another part-time contract⁴. It is a closed list, not an illustration: without one of the three there is no right to renounce. And renouncing the pact ends the complementary hours, not the contract.

A hole in the article, and a recent reform that is not this one

Two things worth knowing before reading article 12 on your own.

The first: it has no paragraph 3. Where it was, the text reads «(Repealed)». It was struck by the sole repealing provision.2 of Royal Decree-Law 32/2021 with effect from 30 March 2022⁶, and what it said was that a part-time contract for fixed and periodic work was deemed to be of indefinite duration. That figure is today the permanent seasonal contract.

The second: the article was amended recently, but not in the part this page is about. Article 2 of Royal Decree-Law 11/2024 rewrote paragraphs 6 and 7 and added a paragraph 8, with effect from 1 April 2025⁷, and all of it is partial retirement and the relief contract. Paragraphs 4 and 5, which govern part-time work proper and complementary hours, were left untouched.

A worked example with real numbers

An indefinite contract of 20 hours a week, in a company whose full-time week is 40.

The pacted cap of art. 12.5.c) is 20 × 30 % = 6 hours. The voluntary cap of letter g) is 20 × 15 % = 3 hours, and it is not deducted from the first, so the complementary total is 9 hours: on a 20-hour contract you can be asked for 29 in a week. The headroom to the full-time week is 20 hours, well above those 9, so here the percentage binds.

At agreement maxima (60 % and 30 %) the same 20 hours give 12 + 6 = 18 hours and a ceiling of 38. And the extreme case is a 21-hour contract at those maxima: 12.6 + 6.3 = 18.9 hours of complementary time against a headroom of 19, so the percentage still binds by a tenth of an hour and the lawful total reaches 39.9 hours a week. A «part-time» contract of 21 hours can end up working 39.9.

And if that same 20-hour contract were fixed-term rather than indefinite, it would reach only 26 hours, because the voluntary layer of letter g) does not exist outside an indefinite contract. In this respect the more secure contract is the more exposed one.