The Supreme Court has confirmed that a company may communicate by email the end of teleworking and activate from that moment the legal period for challenging the decision, even though employees still have several weeks before returning in person to their jobs. This is established by a recent ruling from the Labour Chamber which dismissed the appeal filed by CCOO and UGT against Caterpillar Energy Solutions, a company that eliminated the weekly remote work day that 36 employees at its Madrid and Vigo sites enjoyed. The decisive reason has not been only the company’s ability to reorganize its activity, but that the unions went to court when the 20 business days provided for by labor legislation had already elapsed.
The dispute began on 9 April 2025, when management sent an email to the entire workforce announcing that, starting on June 2, workers should return to the office the five days of the week. The communication responded to a directive from the US parent company and justified the change by the need to strengthen collaboration between teams and improve efficiency. In addition, it expressly warned that the new model would be mandatory and that compliance would be taken into account in performance evaluations. Although nearly two months still remained before its implementation, the Supreme Court considers that that first message already contained a clear, definitive, and sufficiently specific business decision to start the claim period.
The ruling, published this week and reported by The Digital Law, confirms the criterion that the National Court had set in September 2025. The justices conclude that the trade union lawsuit arrived too late because it should have been filed within the 20 business days following the written notification of 9 April, without waiting for the effective return date to the offices or for subsequent communications from the company.
The email of 9 April was decisive: the second message did not restart the periods
The workers of Caterpillar had begun to enjoy teleworking in January 2023, when the company implemented a voluntary system that allowed working from home one day a week. At first, the measure was temporary in nature and was planned until December 31 of that same year. However, the company continued allowing it throughout 2024 and the first months of 2025, until it announced its removal. This continuity led the unions to argue that remote work had been incorporated into the workforce’s working conditions and that it could not be withdrawn unilaterally without following the corresponding legal procedure.
After receiving the April email, the Madrid works council conveyed its disagreement to management in a communication sent on May 13, 2025, in which it considered the removal of remote work unjustified. The company responded on May 22 and reiterated that the decision came from the group’s management and that all employees had to return to work fully in-person. CCOO interpreted this second communication as the definitive confirmation of the change and filed a collective dispute lawsuit on June 19, to which UGT attached itself.
However, the Supreme Court understands that the message of May 22 was a simple reminder and not a new business decision. The communication of April 9 already specified what was going to change, who it affected, when it would take effect, and that compliance would be mandatory. Therefore, the deadline had started to run on April 10, the day after the first notification, and was not reopened by the subsequent response from the company. The magistrates also reject the union argument that the initial communication was a general guideline pending clarification, since any additional instructions announced by the company’s managers did not alter the essential content of the decision.
The ruling has another relevant consequence: the absence of a consultation period does not prevent the deadline for filing a lawsuit from running. UGT had argued that the company could not benefit from the expiry because it had omitted the procedure required for substantial modifications to working conditions. However, the Supreme Court recalls that Article 138 of the Law regulating the social jurisdiction expressly sets the 20 working-day period even when the employer has not followed the procedure provided for in Article 41 of the Workers’ Statute. In this way, the possible existence of irregularities in the company’s actions does not eliminate the obligation to appeal within the legal timeframe.
Can the company take away your teleworking after several years?
The decision also addresses another important issue: whether maintaining a work improvement for an extended period automatically turns that advantage into an acquired right. The unions argued that teleworking had become a more beneficial condition by being maintained for around fifteen months after the initially scheduled date for its end. However, the court considers that this extension does not, by itself, demonstrate that the company intended to permanently incorporate remote work into the contracts.
For a more beneficial condition to exist, a business will to recognize a right that becomes part of the employment relationship must be proven, something that cannot be inferred solely from the length of time during which a particular practice has been allowed. In this case, the magistrates consider that the company had simply tolerated the continuation of a measure that had been announced from the beginning as temporary. In any case, they add that even if teleworking had become a more beneficial condition, the action brought by the unions would also have been out of time.
There is also a fundamental difference with workers who have recognized regular telework arrangements through a written agreement. The Law 10/2021, on distance work considers remote work to be regular when it covers at least the 30% of working hours during a reference period of three months, or the corresponding proportional percentage depending on the duration of the contract. One day of telework in a five-day work week normally represents 20%, so the system applied at Caterpillar fell outside that specific scheme.
In contrast, when there is an individual distance-work agreement subject to Law 10/2021, the modification of agreed conditions, including the percentage of on-site presence, requires an agreement between the company and the worker. Therefore, the judgment does not mean that all companies can eliminate any form of telework through a simple email. The answer depends on the agreed conditions, the proportion of working hours carried out remotely, and the applicable regulations.
What to do if you receive an email announcing the end of telework
The main practical consequence of this judgment is that workers and their representatives should not wait until the day a labor modification takes effect to check their possibilities for making a claim. When the company communicates in writing a final decision that substantially alters working conditions, the 20 working-day period may begin the next day after notification, even if an adaptation period is granted before applying the change.
Therefore, if a company announces the withdrawal of telework, it is advisable to keep the original email with its date, sender, and full content, in addition to the contract, the distance-work agreements, prior communications, and any document that allows the conditions that were in force to be verified. It is also important to check whether the decision is final or whether it is only a proposal pending negotiation, since not every informal communication automatically triggers the statute of limitations deadline.
In the case of a substantial modification, the worker may request advice from their trade union representatives or from a specialized professional to determine how to challenge the measure. The 20 days are working days, not calendar days, and their calculation must be carried out in accordance with the applicable procedural rules. If there is genuine written and express communication, waiting for the company to respond to a protest or to send a second message may cause the judicial action to become time-barred.
The Caterpillar ruling thus leaves a warning for employees who work from home: the right to appeal a labor modification can begin to run out before the change actually affects their daily routine. In this case, the company communicated in April the scheduled in-person return for June, but the unions did not go to the courts until June 19. The Supreme Court considers that the lawsuit was filed out of time and confirms the ruling of the National High Court, leaving in place the decision that allowed the weekly day of telework to be withdrawn from the 36 affected workers.