Two things get mixed up. Your employer moving you to different tasks within your professional group is common and lawful. Changing your hours, your shift or taking you out of your group is no longer just another order: it is a change to your contract, with rules, deadlines and an exit with compensation.
Change of duties: it depends on your professional group
Article 39 of the Estatuto de los Trabajadores (Workers Statute) regulates functional mobility. Within your professional group (grupo profesional), the employer can assign you different tasks as long as it respects your qualifications and your dignity (39.1). The group is defined by your convenio colectivo (collective agreement), not by the name of your job.
Outside your group there are more limits (39.2). Higher or lower duties can only be assigned if:
- there are technical or organisational reasons that justify it,
- it is for the minimum time needed,
- and the employer tells the workers’ representatives the decision and its reasons.
If you are given higher duties, you are paid for the duties you actually perform (39.3). If they are lower, you keep your original pay. If the higher duties go on for more than six months in a year or eight months in two years, you can claim promotion or the filling of the vacancy, plus the pay difference. One more protection: you cannot be dismissed for supervening incompetence or failure to adapt when you are doing unusual duties because of functional mobility (39.3).
Any other change of duties that does not fit here needs your agreement or must follow the rules of article 41 (39.4).
Change of hours, working day or shifts: a substantial modification
Article 41.1 lists as substantial modifications, among others: the working day, the schedule and distribution of working time, the shift system, the pay system and duties that exceed functional mobility. To make them the employer needs proven economic, technical, organisational or production reasons, related to competitiveness, productivity or work organisation.
If it affects few people, it is individual. It becomes collective if, over 90 days, it affects at least 10 workers (companies under 100 staff), 10% of the workforce (100 to 300) or 30 (over 300). A collective change requires a consultation period of up to 15 days with the representatives.
Note that not every change of hours goes through article 41. The collective agreement may provide for irregular distribution of working time across the year and, absent an agreement, the employer may distribute 10% of the working day irregularly. In that case you must know the day and hour with at least five days’ notice (art. 34.2).
If the issue concerns hours added to your working day, check the legal limit and pay for overtime in Spain alongside your records.
What you can do if the change harms you
For an individual modification, the employer must notify you and your representatives at least 15 days in advance (41.3). You then have three options:
| Option | What it means | Deadline |
|---|---|---|
| Accept | The change applies | From the date it takes effect |
| Challenge it | Labour court; the change applies in the meantime | 20 working days from the day after notification (art. 59.4) |
| End the contract | Compensation of 20 days’ salary per year, max. 9 months | The Statute sets no express deadline; do not let it pass without advice |
Ending the contract is only possible if the change harms you and affects your working day, schedule, shifts, pay or duties (41.3). If the judge declares the change unjustified, you are entitled to return to your previous conditions. If the employer splits changes into 90-day blocks to stay under the collective thresholds, with no new reasons, the Statute treats this as fraud and declares them void.
An example with figures
Carlos has been with the company for 4 years and 6 months and earns €1,800 gross a month (€21,600 a year). He works 8:00 to 16:00. On 2 November 2026 he is told he is moving to the afternoon shift.
| Item | Calculation | Result |
|---|---|---|
| Earliest effective date | 2 November + 15 days | 17 November 2026 |
| Daily salary | 21,600 / 365 | €59.18 |
| Days of compensation | 20 × 4.5 | 90 days |
| Compensation if he ends the contract | 90 × 59.18 | €5,326.03 |
| Cap of 9 months’ pay | 9 × 1,800 | €16,200 (not reached) |
If he challenges, he has 20 working days from 3 November. Count them as explained in the dismissal claim deadline: the counting logic is the same, with no Saturdays, Sundays or public holidays.
If a relative is admitted to hospital, distinguish family hospitalisation leave in Spain from holiday and other types of leave.
How to respond in writing
When the notice arrives, do not rely on a verbal conversation. Ask for the decision in writing, with the reason and the date it takes effect. When you sign for receipt, write «received, not in agreement» if you disagree: signing only proves they gave it to you. Then email the company and, if you have them, your representatives: say you do not accept the change, that you consider it a substantial modification without a proven reason and that you reserve the appropriate actions. Keep your previous schedule, your payslips and your contract, which are the proof of what changed.
While it is being resolved, the change is carried out (art. 41.3). Do not ignore it without advice: the employer could treat that as a breach.
Why your case may be different
- Your collective agreement may regulate shifts and hours. If it provides for rotation or changes with different notice, read it before deciding.
- Your contract may include the schedule or duties. What was expressly agreed carries more weight than what the company has done in practice.
- Work-life balance: if the change clashes with a reduction or adaptation of hours you already have, the protection is different; see how to request a working-time adaptation.
- If the employer cannot prove the reason, the modification can be declared unjustified.
If the employer refuses to restore your conditions after a ruling that declares the modification unjustified, article 50.1.c lets you ask to end the contract with unfair-dismissal compensation.
This is general information and not a substitute for a professional. With deadlines or money at stake, speak to an employment lawyer (abogado laboralista) or a union before signing or refusing anything.