I had a very disappointing experience at this FedEx location. My company regularly ships packages using FedEx labels and occasionally reuses shipping boxes, including UPS-branded boxes.
When I brought in my package, the employee immediately responded in a rude tone, saying, "THIS IS A UPS BOX," as if I was doing something wrong. Afterward, she processed the shipment with an attitude that made it feel like they were doing me a personal favor rather than simply providing the service I paid for.
Both FedEx and UPS generally accept customer-provided packaging, including competitor-branded boxes except USPS, as long as the package has the correct shipping label and is suitable for transit. If this location has its own policy regarding UPS-branded boxes, that's perfectly fine—but employees should communicate that professionally and accurately.
I expect FedEx employees to be knowledgeable about shipping policies and to treat customers with basic courtesy and respect.