Company numbers can only be generated when Companies House are open. Their hours are 9 am, to 5 pm, Monday to Friday. If you order a company outside of these hours we will submit it first thing on the next working morning.
Assuming you place your order during normal business hours we will check over the details you have submitted to make sure there are no obvious issues (e.g. a sensitive word in the name). We then submit your company formation directly into the Companies House systems. From that point it typically takes 3 to 5 hours to get your company number back.