Short answer. Usually no, unless your employer has already recognised the union's right to check-off. The Labor Code allows a union-dues deduction in only two situations: the employer recognises the check-off, or you personally authorise it in writing. Absent one of these, the deduction is unlawful and the amount is recoverable.
What the law says
For union dues, in cases where the right of the worker or his union to check-off has been recognized by the employer or authorized in writing by the individual worker concerned
Labor Code, Article 113 — Wage Deductions. Read the full provision →
The rule starts with a flat prohibition
Read the provision from the top and you see that it is written as a ban with narrow exits, not as a licence. The law says that no employer, acting for himself or for anyone else, may deduct anything from an employee's wages except in the listed situations. That structure matters when you are arguing about your payslip. The employer does not get to ask you to prove that the deduction was wrong; the employer has to point to one of the exceptions and show that it applies to you. If your company cannot identify which exception covers the item taken from your pay, the deduction has no legal basis at all, whatever the payroll system prints beside it.
What counts as a valid check-off
For union dues specifically, the statute recognises two independent routes. The first is a check-off right that the employer has recognised — typically through the collective bargaining agreement, where the company agrees to collect dues at source and remit them to the union. The second is a written authorisation signed by you as an individual worker. Because the two routes are stated in the alternative, a company that operates under a CBA check-off clause does not separately need your signature for ordinary dues. That is why many union members are surprised to find dues coming out of their pay although they never signed anything: the collective instrument, not the individual one, is doing the work.
Where employers most often go wrong
Trouble usually arises with charges that are not ordinary dues at all — special assessments, attorney's fees taken out of a negotiated benefit, agency fees, fines imposed by a union body, or arrears collected in a lump sum. These are not automatically swept in by a general check-off clause, and treating them as if they were is the most common defect. A second frequent error is timing: a written authorisation is a personal act, so a worker who has withdrawn it cannot be treated as still bound by it. A third is scope, where a company deducts on the strength of a clause that has already expired with the agreement that contained it.
What you can do, and what the rule does not cover
Start by asking, in writing, for the legal basis of the deduction and for a copy of the check-off clause or of the authorisation the company says you signed. A demand on record is useful whether the dispute ends up with the union, with the labour authorities, or nowhere. An unlawful deduction is ordinarily recoverable as unpaid wages. Be realistic about the limits, though. This provision governs deductions from wages; it does not decide whether you must belong to the union in the first place, whether a union security clause is enforceable against you, or whether the dues themselves were validly imposed inside the organisation. Those are separate questions with separate rules, and the outcome of any particular case depends on its own facts and documents.