With the lodgment deferral function in Online services for agents launched and working, the ATO will start the final transition by removing the ability to request lodgment deferrals via previous methods.
From 31 July 2023:

• Phone deferrals will no longer be available. Callers will be directed to use the lodgment deferral function. Note: Lodgment deferral requested via the phone service was limited to lodgment deferrals requests that met low-risk (agent-assessed) guidelines and a maximum of 5 clients. 
• Lodgment deferral spreadsheet application forms will be removed from the ATO website. 
• Information, guides and videos are available to help agents apply using the lodgment deferral function.

From 1 September 2023, the ATO will no longer accept lodgment deferral requests submitted using the spreadsheet application forms. If you already have a spreadsheet application form and submit it through Practice mail by 31 August 2023, the ATO will process your request. After that date, you need to apply using the lodgment deferral function.

The ATO understands that any improvement means a change to how you do things in your practice. So, if you haven't made the switch, the following will support you:

• Applying for a lodgment deferral – information and instructional videos showing how to request a single or multiple deferrals
• Online services for agents user guide – detailed instructions to guide you through the process
• Help aside information in Online services for agents – available on every screen to help you as you go.