Hi Jillian,
Hope you are well!
Unfortunately, there is no third way to split the payment between multiple credit cards for the invitees other than planner allowing partial payments or recording offline payments.
I understand your perspective and apologize for any inconvenience. But, it sounds like a great feedback. I suggest you to post this as an Idea/feedback for our product team by going to Cvent Community > Participate > Product Ideas.
We encourage you to always submit your ideas or any challenges you face while working with the product. As it also help our Product Development team to review the possibilities and if it works we may try to incorporate such changes in our future releases.
Please let us know if you have any further questions.
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Raashi Semwal Khati
Senior Quality Analyst
Cvent
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