Kindly help me with below:I have filed STP for FY 2023-24 but still its status id "PENDING". WHat may be the reson? How can I know the reason?

Welcome to the Community!

The maximum waiting time for a pay event submission in QuickBooks Online Payroll is up to 48-72 hours from the submission date. We should see the updated status after 3 business days. There could be a large number of lodgements to the ATO that cause the pending status. 

Another reason also the pay event shows pending is if there is a maintenance in the ATO's website: https://www.ato.gov.au/online-services/system-maintenance.

If it is more than 72 business hours from the time you've submitted the pay event and the status is still pending, I recommend contacting out Customer Care Team. They have the right tools to check your payroll file. 

Drop by again in the Community if you have other QBO concerns. I am around to help you.