Is the onus on the employer to tell the temporary worker or is it up to the temporary worker to make a claim?
Good practice says you should take the initiative and have that discussion with the Agency that supplies the temporary worker as soon as you become aware there is a discrepancy. The Agency should comply and give you the hourly rate they are paying the temporary worker which will allow you to make the comparison even if a claim has not been made. Alterenatively you may prefer to agree with the Agency how the temporary worker’s rate can be increased but with limited or no additional cost to your business.
However, it is really up to the temporary worker to make a claim via the Agency and for the Agency then to contact you with the claim.
How do I make a comparison?
Ask all the Agencies you work with to provide you with the actual hourly rate for each temporary worker who is working within your premises.
Identify a comparable permanent employee and work out their actual hourly rate by dividing their full time annual (or pro-rata if part time) salary by 52 weeks by the number of hours they work each week.

