Dynamics GP - Automatically Print separate remittance for check with more than 12 lines in remittance

This cannot be done, you must tick "Separate Remittance" when printing your checks.

In cases where there are too many lines to print on the remittance,when printing checks you need to

• tick “Separate Remittance”
• Print your checks as normal
• When the screen comes up to post checks, click “process”
• A new windows will open to prompt for a separate remittance. Select Remittance form, and print document, then click Process
• This will prompt you to print the remittance separately.

To control the number of records displayed on the check stub

https://community.dynamics.com/gp/f/32/t/181070

Go to LAyout>Tools>Section Options

Make sure that in Report Writer, your "Remittance Header" has a "Records Per Report Body" set to 12, and that the "No Break At Record Count" checkbox is unmarked.

This is the default setup for check formats.