Short answer. Article 117 of the Labor Code. It makes it unlawful to deduct anything from an employee's wages for the benefit of the employer or his representative or intermediary as consideration for a promise of employment or of retention in employment — which is exactly what buying your job back every payday is.
What the law says
It shall be unlawful to make any deduction from the wages of any employee for the benefit of the employer or his representative or intermediary as consideration of a promise of employment or retention in employment.
Labor Code, Article 117 — Deduction To Ensure Employment. Read the full provision →
The word that catches your supervisor
Employers often answer this complaint by saying the company never received a peso, and that whatever a line manager arranged privately is not its doing. The article closes that door in advance. It covers a deduction made for the benefit of the employer or his representative or intermediary, so the money need not reach the company at all. A supervisor, a team leader, a foreman or an agency coordinator who pockets the cut is squarely within the wording, and the arrangement does not become lawful because it was struck informally rather than run through payroll.
What 'consideration of a promise of employment' means
The vice the article names is the exchange. The deduction is unlawful because it is the price of a job — you pay, and in return you are hired, kept on, renewed or put back on the schedule. That is different from an ordinary dispute about whether a deduction was properly authorised. Here the payment buys nothing but the continuation of work you were already entitled to keep on the terms you were engaged under, and the law treats an employee's own wages as an unlawful currency for it.
It bites at hiring as much as at retention
The provision names both a promise of employment and retention in employment, so it reaches the demand made before you started as well as the one made every fifteenth of the month afterwards. It also does not care what the sum is called. A 'processing share', a contribution to an office fund, a standing reimbursement of the person who recommended you — if the real bargain is that the money keeps you employed, the label does not save it. Nor does your having gone along with it: this is a prohibited arrangement, not a negotiable one.
Building a record of a demand made in person
Demands like this are rarely written down, which is the difficulty. Keep every payslip alongside your bank credits, because a steady gap between the two is the clearest objective sign. Save any message that sets the amount or the date, however casual. Note when each demand was made, how much was taken, in what form, and whether anyone else was present or subject to the same arrangement — several employees describing the same practice is far stronger than one. Bring that record when you consult a lawyer, before you confront the person taking the cut.