To invite clients and manage their rights to enter payroll data, you will need to invite one or more users within the Permissions page: Inviting Clients and Customising Permissions.
Once you toggle the option Allow Client to Submit Payroll Data, they will obtain new features. For reference, you can see the Client's perspective here: Client Collaboration: Data Entry Process as a Client
Reviewing the Client's Data
Once the client has submitted the data required and submitted, you will get a notification in your inbox.
Kindly note how the client can submit notes for you in the screenshot above.
Once you have reviewed the data submitted by the client, you can calculate and save payslips. After you've completed your payroll, you can conclude, or Sending Payroll for Review