A typical day at Next will consist of mind-numbingly menial tasks such as putting out endless pairs of jeans, followed by being moaned at by your 17 year old line manager for not putting them out in precisely the correct manner. Luckily you won't get too much of this from the senior management, as they rarely ever show their faces on the shop floor, I imagine they consider themselves far too important for such trivial matters.
If you do decide to work for Next then you'd better not make any plans outside of work...ever. They seem to change your work rota on a daily basis, in one instance my shift was changed a matter of hours before I was due to be in. Also, be prepared for baffling and draconian rules, such as not using the escalator to get to the stock room, I guess that returning out of breath 15 minutes later with a customer's item is more professional than using an escalator, who knew?
As for the famous staff discount, I was told I would have to wait about a month for it. Furthermore, if you are full time your 'allowance' is about £200 (Approx) with 75% off, this means you still have to cough up £50 of your own money for uniform, which is no small sum when you are on Next wages; more commonly known as minimum wage. Avoid this place like the plague, even for a low paid job they are an incredibly poor employer.
