Is it permissible to take the agreed-upon annual increase or the right (due) by any means, including illicit means, if the employer does not adhere to paying them?

The employment contract between an employee and an employer is a lease contract (ijarah (definition)). If the employee enters a new year without an agreement on new terms, the contract is renewed under the previous terms. The employee has the right to an annual raise if it is due.

It is permissible for the employee to take their right from the employer without the employer's knowledge (mas’alat al-dhafar - the issue of gaining one's right by seizing it) if three conditions are met: that they are unable to obtain their right through litigation, that they do not take more than their right, and that they are safe from disgrace.