Company Registration agents are really no different to Company Formation Agents – they just operate under a different title.
Company formed to order
It may be that you are forming a charity, another company under the umbrella of a parent company, or one that will have a specific share structure. Of course it may be that you wish to have a company that you feel is distinctly yours having had no previous shareholders or directors. There is merit in this but the costs involved will be more, as will the time element. Whereas if you acquire an off the shelf company you will be able to trade with it within a 48 hour period, a specifically formed company will take a few weeks to be able operational.
Company Registration