When you create an application form, you can enable the credit card form from Membership > Settings > Application Form > Payment Options. You can also add an Application Fee from there.
This way, when your members fill in the application form and choose a membership plan, they will be redirected to another page where they see the credit card form to make their payment for the membership fees and application fees if applicable.
Sometimes, members do not enter their credit card information on this page and close the page. This will still trigger the application to be received as the member completed all the initial steps for the application on the first page.
For these instances, a question arises:
Can I make a requirement for all paying members to fill in their credit card details before submitting or sending their applications?
The answer is No because you cannot know if the card is valid or has an available balance before you charge the card. In order to charge the card, the application must be approved.
Therefore you have two options here:
You can auto-approve applications and the ones with successful payments are automatically approved, while the ones with incorrect or no card go under the Applications tab where you'll need to review. You can either reach out to the member to ask for the card details and ask them to update their details or simply delete the application.
You can manually approve applications. If they don't have a card on file, you can reach out to them or simply delete their application.