We have just become ltd. Manily because we had our own small business and now we have taken over my partners fathers compny. There are many benefits of going Ltd. One is that you pay yourself under the PAYE system, so you can decide how much you take. ANd if you only take say £20K, you can pay yourself dividends through the year, which you pay only 10% tax. ALso i think if you are going for bigger contracts even though we are quite a small company in comparision, it makes you appear that you are a bigger company. As i said we have only just done this so i will keep you posted. Also you can claim more things like bother your mobile phone and office phone. Where as a sole trader you can only claim for one of these. It is best to speak to an accountant, who can advise you more.