I work at a consumer registrar, the only thing you need to do in order for us to hand over control of a domain to you is put a company logo on a word document, stamp it and fax it to us.
This does not apply to larger clients, but then if you're already looking for that kind of service it makes sense to go to a company that specialises in that.
This does not apply to larger clients, but then if you're already looking for that kind of service it makes sense to go to a company that specialises in that.