Hi Luis Dominguez,
Thanks for getting back to us. You can add multiple attachments to your forms in QuickBooks Online. However, as you've mentioned this feature will not work specifically to your business needs. I recommend submitting a suggestion to our Development team by going to > Settings ⚙ > Feedback.
Others are more than welcome to chime in and offer any additional tips or tricks that would be of benefit to your specific needs.
We're always here to help, when other questions may arise.
