BC Deductions

An employer must make deductions from wages required by law (e.g. income tax, EI, CPP). Other deductions may be made if the employee agrees in writing.
An employer cannot deduct any of the employer’s business costs from wages. This includes cash shortages, breakage, damage to company property or when a customer leaves without paying.

Reprinted from http://www.labour.gov.bc.ca/esb/esaguide/#2