New PAYE registration

I am a third party payroll provider and after creating an account, I now have my Gateway User ID, Password and Agent ID. How do I register with PAYE so that I can gain access to file and remit on my clients behalf?

Hi Cameron Hanna,
How to enrol a service
To enrol a tax service, you must:
1.    Sign into your HMRC online services account using your Government Gateway user ID and password.
2.    Select ‘Services you can add’ in the left hand menu.
3.    Find the service you want in the list and click on ‘Enrol for service’.
4.    Enter your agent code and postcode when asked.
You’ll then see a confirmation screen, confirming that you have enrolled a tax service.
To activate the tax service, you’ll need an activation code.
You’ll get this in the post from HMRC and it can take up to 7 days to arrive.
Thank you.

Ok, how do I get an agent code? When I setup the HMRC Services account I was given an agent ID, but it seems way too long compared to example agent code that is given when on the agent code and zip code screen.

Hi Cameron Hanna,
Please go to the following website:-
https://www.tax.service.gov.uk/agent-epaye-registration/start?
Thank you.