The ATO Validates your STP file and data submission at a number of levels.
Some of the tests include:
1. File header information
Is the file in the right format?
Was the file submitted through an approved secure channel?
Did a valid person authorise the file?
2. Employer information
W1 & W2 fields.
3. Employee records
4. Data validation
The ATO will eventually be conducting evaluation of the numbers, and begin to raise queries when the numbers don't look right.
In the coming months, the validation checks that the ATO performs will return validation reports about any files which are outrightly rejected, or where the file is accepted but some of the data is incorrect – i.e., maybe one of the employees' TFNs is not valid.
The ATO will provide a validation report to your software if your software has a direct, secure and authorised communication channel to the ATO. If that channel is not acceptable, then the ATO will provide that validation report to the employer. If the software channel is acceptable, the software company should be providing you with that report in a form that enables you to fix any errors.
When the error has been fixed in your payroll system (the ‘source of truth’) you are not required to resubmit the file. The Single Touch Payroll design does not allow for a file to be resubmitted (see below about ‘Full File Replacements’). You fix your system, and the information will be fixed in the next file submitted for that employee.
Alternatively, if the error is to an employee's information that will appear on their myGov record, you could submit an ‘Update’ file to the ATO (if your software has that function).
A Full File Replacement can be used in cases where the very last file is to be fully replaced. Note that it is only the very last file that was submitted by each BMS (Business Management System / Payroll software) that can be replaced.
An employee's information can be fixed in the next payrun, or as mentioned by an ‘Update event’. The Employer information for W1 or W2 that was wrong can be fixed at the time of preparing and lodging the next BAS.