If the employer tells an employee to do someone else’s job in a higher category of pay than the employee’s own job, then the employee should get the higher wage if he/she performs this work for an extended number of days. (“Equal pay for work of Equal value’).
An employer can ask an employee to do work below his or her own pay category, but the employee should not get paid less than his or her own normal wage and also provided the employer is not doing this to make the employee’s life at work intolerable.
Section 6 – particularly subsection 4 – of the BCEA deals with equal pay for equal work with grievances for unfair discrimination being an option if a commissioner or the courts deem the employee to be correct.