BYOD is a good deal for the business, can work out less well for the employee. We have an option to go BYOD, and I've swapped back to a company supplied device, because of the difficulty in claiming expenses back for the data and calls that I have used. The long calls to a specific number were easy to claim back but the lots of short calls which don't get itemised weren't - same for data. It was mainly overseas travel where I was getting hammered so may not work that way for everyone.