How is handling applied for split shipments?

Topic summary

Clarification sought on how handling fees behave with split shipping across carriers. A customer orders two products, one via UPS (United Parcel Service) and one via USPS (United States Postal Service), each with a flat handling charge; the poster asks if both handling charges will be applied when using split shipping (items in one order shipped separately).

They also ask if there’s a way to apply only a single handling charge per order despite multiple shipments/carriers.

Context: checkout and shipping settings within Payments & Shipping/Fulfilment.

No responses or confirmed settings provided; the question remains open without a resolution.

Summarized with AI on December 13. AI used: gpt-5.

If I’m using split shipping and a customer orders 1 product shipped via UPS and 1 product via USPS and they both have a flat handling charge will both charges be applied?

If they are both applied, is there a way to only have one charge per order even if split?