Umbrella firm = contractor. I've contracted in IT in the past. I used a company called Parasol - have a look at their website. The company pays them, they pay you minus taxes and NI. Very simple and easy to do. However, if you're going to contract for more than a year or two then it is best to set up your own company to bill your 'employer'. As a contractor you get no normal company benefits such as holidays, sick pay, pension - so add the numbers up carefully. A contractor role should pay a higher rate to cover these things.