After registering a company, it is important to find out whether or not you need to register as an employer. Even if you're the only person working in your newly set up limited company you might still need to register as an employer as you'll be considered both an employer and an employee.
If you meet one of these requirements then you must register as an employer and you will need to provide HMRC with the following:
Most employers can register with HMRC by telephone or online. The easiest way to register is via HMRC website as it gives you clear instructions on how to register. You will be unable to register online if you have a simplified PAYE scheme with more than 10 employees, your limited company has more than 9 Directors or you're in partnership with more than 10 partners. In that case you'll have to register over the phone, by contacting HMRC's New Employer Helpline. If your payroll is unusually different then you will need to register through an HMRC office.
Once you're registered as a new employer you'll need to familiarise yourself with the guidelines, forms and returns that are needed to perform your payroll. There is a payroll system that is available on the HMRC website that will allow you to file the forms and returns online.