HMRC Access

We recently acquired a limited company and are taking over their payroll in November. They currently use a 3rd party for their payroll and the 3rd party has an agent log in to be able to access P6s and Student loan information. There is no-one within the company we have acquired who knows the Gateway ID and password that we need to be able to access the information for payroll. How can we get access HMRC services to be able to get the information that we need?

Hi payrollKate,
Please contact our Online Services Helpdesk on 0300 200 3600 for further advice. 
Technical support with HMRC online services
Thank you.