There is no clear information. One time I used it, the shipment went through from the US to Canada and I never got a bill or anything. The second time I tried, UPS sent me an email directly once the package was ready for clearance and asked if they wanted me to clear the shipment or send me paperwork do DIY.
I can't find clear info on this.
Hey there @KKC,
Thanks for joining us here in the community! We are thrilled to have you with us.
For specifics about this billing process, my recommendation would be to reach out to your carrier account rep. We have seen carriers use both methods, so it would be best to reach out to them for your specific account details.
This is what do have available about DDP billing support in ShipStation.