What if I have a Withholding Payer Number (WPN)?
You can only enter an ABN/ACN into the Business details in MYOB Essentials. If you only have a WPN, you won't be able set up your business in MYOB Essentials.
If you're trying to set up MYOB Essentials so you can lodge your payroll information to the ATO via Single Touch Payroll, you'll need an ABN. If you don't have one you'll need to contact the ATO about how you can report to them. You might need to lodge your payroll information via a tax agent.
All business are different, so for specific advice on your needs you can ask the experts on the community forum or contact an MYOB Partner who will be happy to help.