Testing Lab of Power Supply/ IT / AV Products

A desktop power supply (external desktop PSU) sold in the United States typically needs UL safety certification (UL 62368-1) before major retailers and e-commerce platforms will accept it. Unlike the EU's self-declared CE model, the US market relies heavily on third-party safety listing—and Amazon US actively requests a valid UL report for power products. This guide walks through the process, documents, cost and timeline drivers, and marketplace compliance for a desktop PSU in North America.

Which certificate does a desktop PSU need for the US

For the US and North American market, a desktop power supply primarily needs:

• UL 62368-1 (Safety): the US standard for AV, IT and communication equipment safety—covers insulation, clearance and creepage, temperature rise and fire enclosure. Managed through a Nationally Recognized Testing Laboratory (NRTL) such as UL.
• FCC (EMC, Part 15B): electromagnetic compatibility for the US market—usually a self-declaration, but still required for listing.

If the PSU model is already UL-recognized or listed, a derivative model can often reuse much of the existing report—a useful cost lever. The safety test is the gate that retailers check first.Desktop PSU UL certification process

Step-by-step process

1. Confirm the spec—input voltage, output power, efficiency, enclosure material.
2. Prepare technical files—schematics, PCB layout, BOM, component certs.
3. Submit samples for safety (UL 62368-1) and EMC (FCC Part 15B) testing.
4. Close deviations, obtain the UL report / listing, and register the model.
5. Mark the product with the UL listing mark and apply the FCC label.

Safety and EMC can run in parallel, but the safety closure (deviation resolution) is often the longest step.Desktop PSU UL document checklist

Documents you need to prepare

• Product specification (input/output, power, efficiency)
• Schematics, PCB layout, BOM list
• Critical component certs (transformer, optocoupler, Y-cap, fuse)
• English user manual (safety instructions)
• Samples: 2–3 units for safety, 2–3 for EMC

What drives cost and timeline

The cost of desktop PSU UL certification is driven by whether the model is a derivative of an existing certified PSU, the output power, and the number of deviation rounds. A derivative of a listed model reuses much of the report; a fully new design needs complete safety testing. Timeline follows the same logic—deviation closure is usually the longest step, and document completeness drives report preparation. A precise quote needs the full spec and BOM.Desktop PSU UL cost estimate

Amazon US compliance notes

• Upload the UL report (or listing) and the FCC declaration to the compliance portal.
• The product label must show the UL listing mark and the FCC mark.
• Amazon may request the test report directly during listing review—keep it ready.

Amazon US checks the UL report against the model—an unlisted or mismatched PSU can be removed from sale.

Frequently asked questions

This article is for industry reference only. Certification cost and timeline vary by product; please consult a professional engineer for an actual assessment.

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