The process for submitting STP2 batches is identical to the STP1 submission method.
See submitting STP batches.
There are some changes specific for STP2.
The current version of STP is displayed in the submission workflow.
Previous BMS Identifier
When STP is submitted the ATO records a "BMS Identifer". You now have the ability to enter the ATO identifier so that you may update previous STP submissons. These may have been performed by previous software systems or other CAC numbers. There may be rare circumstances in which you may use this feature.