Thanks, everyone, for your advice!
cpa1and Rick25 y'all's strategy is what we ended up implementing. We're adding it as an optional, but pre-selected line item with a description as to what it is and how to avoid it. That way they have to take action in order to remove it, which would give me confidence that they read and understood payment options.
I also added a clause in our addendum describing the surcharge process, adding that if they exclude the line item but pay with a credit card anyway upon invoicing, we'll send them an additional invoice for the surcharge. Not that everyone reads their addendum....
So I also added reminders about this in the auto emails for new quotes, quote approvals, booking confirmations, and invoices. Hopefully that does the trick!
I’ve used a lot of CRMs and have been really impressed with Jobber so far, but I’d love to see this option added. This work-around meets most of our goals, but I do have to overcommunicate with clients to make sure they understand the surcharge item on their invoices, which can be a bit much. Plus, it makes the upfront cost on their estimate look unnecessarily inflated which can make for an offputting first impression when competing for bids.
Again, thanks for the thoughts!
