For people working as consultants, have you been asked to provide your own equipment (laptop and accessories) for work? if yes, how do you bill them for it?

I just build it into the day rate. Clients pay for my full capability while include time, kit, software, etc.

Tools aren't really that expensive when compared to time.

I would prefer to provide my own equipment, mainly because most IT departments provide next to useless equipment and refuse to upgrade it because "it doesnt fit in with our 3-year desktop refresh plan".

If you have to buy something extra just for that job (eg I purchased a Raspberry Pi for one job because they wanted to run Docker images on ARM and I needed to test) - the path of least resistance is to bill a few extra hours to cover it.

If you've fucked up and given a fixed price amount - you'll probably have to wear it