You can add the built-in "Partner Type" field to your Become a Partner form to allow prospects to specify their desired type of Partnership when applying to join your program. 

Become a Partner Form 

To add the Partner Type field to the Become a Partner form, go to Settings > User & Organization Fields > Organization Field Requirement & Visibility. You'll then select the third checkbox (on the right ) under the "Become a Partner Form" column to make the field visible on the form. 

Organization Field Requirement & Visibility Settings

You can select both checkboxes under the column to make the field visible and required. 

Organization Field Requirement & Visibility Settings 


Can Partner Users update their Organization's Partner Type in Channeltivity? 

Partner Users do not have the ability to update the built-in Partner Type field in their Organization Profile as it is a read-only field to Partners. 

Organization Profile - Partner User View

Related Documentation: 

Partner Types 

What is the difference between "Become a Partner" and "Request Access" forms?