Thanks for this thread. Just adding that this isn’t currently possible in HubSpot Payments checkout flows.
We’re offering a 50% lifetime discount via a code and would love to preload it in the payment link — especially since we promote the discounted price everywhere.
It’s confusing for customers to land on a full-price checkout page and only see the discount after typing the code manually.
It would be great to support something like ?discount=CODE or similar for payment links.
+1 on this request!