Hi there, @t_fox-live-co-uk.
Thank you for posting here in the Community. I can provide some information about adding an employee in QuickBooks Online Advanced Payroll.
Yes, it's possible to add a worker without the information you mention above. If the National Insurance (NI) number for the employee is not available (or the employee is exempt from supplying a NI number), click the 'NIN unknown' box.
- On the left navigation bar, click Payroll.
- Click Add Employee.
- Fill in the necessary information.
- Under Tax and NI Details, search for the National Insurance Number field.
- Put a checkmark on the box beside NIN unknown (NINO).
- Proceed until Finish.
For more information, as well as how to enter personal and employment details, I recommend the following article: Adding an employee in QuickBooks Online Advanced Payroll.
Feel free to hit that Reply button if you have additional questions. Have a great day ahead.