I’m a supplier working at a customer site. Many years ago, the customer outsourced the provision of their IT services, including training, to a 3rd Party company (they are my employer). One of the requirements in the outsourcing contract is to have an on-site training team and I’m part of that team.

The customer, like many companies these days, implements a Dress-down Friday policy where employees are allowed to wear casual clothes. There’s nothing in the employee handbook about exactly what can and cannot be worn so it’s entirely up to the individual to make sure that they dress “casually but appropriately for work”.

The general dress code is fairly casual anyway. On Monday to Thursday, very few people wear suits, very few males wear ties. Friday to most people means jeans rather than trousers or a skirt and a t-shirt rather than a shirt or blouse.

As a customer-facing non-employee, should I join in or should I stick out like a sore thumb? Does it depend on what I’m doing? If I’m delivering a classroom training course should I look “business-like”?

What would you do?