Two parts to this really....1) Reference checks. A CRB check, usually Disclosure Scotland as it's faster. For existing contractors they'll want confirmation from previous agencies of your start and end dates for the last five years. For your first contract they may want similar but for perm employment. They will probably also ask for two personal references from people of "professional" standing I.e. Not just a neighbour or mate.2) docs. Limited company certificate of incorporation, VAT registration certificate, certificate of public and personal liability insurance.you'll also need a business banking account if you plan on getting paid.:-) you will also need a passport to prove your eligibility to work in the UKIn order to complete the CRB ( you do this online with a ref number your agency will give you) you will need to have employment and residence details going back five years.Have you won a contract yet? If you do not have any of the above, there is no need to get them until you get your first contract. They can all be procured in 48 hours, mainly online, fir a total cost of a few hundred pounds. For the insurance I suggest Hiscox. Very credible, decent rates and crucially monthly payment, so you won't start contracting life with a whopping £600 one off fee - just a 50 quid Dire r debit.Almost all fin secs companies will use big agencies who will all have an "on boarding" or "compliance" person who will explain all this to you and coordinate the references and CRB.Been contracting into banks for 7 years now. This is standard at all of them