When UPS charged me a $684 tariff on $355 of vintage computer parts

In Germany, you can pre-register with DHL Express¹ with a bank account and optionally an EORI (Economic operators registration and identification) number, and then they immediately ding your bank account instead of providing their "disbursement service" where they 'benevolently' loan the customs fee to you for a 'minor' fee. I've not found similar options elsewhere, though I would assume they exist but might be corporate-only.

¹ annoyingly enough this doesn't even work with DHL, which is a separate thing from DHL Express in Germany.

This is how it works here in the US as well. If you are using FedEx or UPS for cross-border express shipments, you need to open an account with them and have a credit card on file (or whatever). Then they will deliver first and bill you later, instead of the other way around without an account. This really does make a difference!