Do you have multiple payrolls, where one or more is especially confidential?
Then you’ll need to get separate Employer Registration numbers, one for each Payroll you run.
Under PAYE Modernisation, if you have multiple separate payrolls all linked to the one Employer Registration number, then whenever an RPN file (the new P2C replacement) is requested, you will get the details for all Employees associated with that Employer Registration number, even if they are calculated in different payrolls.
And if you calculate some employees through your in-house payroll while other employees are calculated through a third party bureau, if both payrolls have the same Employer Registration number then the staff running the payrolls will see all details relating to all employees, regardless of whether they are on the internal or the bureau payroll.
This may give rise to concerns about confidentiality and also about GDPR compliance.