According to IRS Publication 1524:
If a partner or representing officer is authorized to sign more than one Form 1065 return, a Multiple Tax Return Listing may be used with Form 8453-P in lieu of sending separate Forms 8453-P. The Multiple Tax Return Listing should include the date, transmitter's name, and telephone number, the 5-digit ETIN and the page number.
The listing should be formatted in a landscape layout to display the 9-digit EIN, Name Control, Tax Period, Gross Receipts, Gross Profits, Ordinary Income, Net Income (rental real estate), and Net Income (other rental activities) of the partnership.
A Multiple Tax Return Listing with a maximum of 500 partnerships may be attached to each Form 8453-P. The signature document for multiple returns must include one (1) Form 8453-P signed by the partner or authorized representative.
Note: If attaching a multiple listing of partnerships to Form 8453-P, please provide the information using a readable font size, such as 12 or higher.
This information applies to all years of the UltimateTax software.