USB-C and cable assembly tariffs, by HTS code

Cable assemblies no longer pay the same stack as power adapters. A USB-C, HDMI, or AV assembly (HTS 8544.42.90) pays an effective 52.6% from China and 27.6% from Vietnam — the 2.6% base, the 25% Section 301 on Chinese origin, and a 25% Section 232 copper duty that has applied to connectorized cable from every origin since 6 April 2026. Coaxial still pays 42.8% / 17.8% and optical fiber 37.5% / 12.5%, because neither is on the copper list. The country-of-origin rules are identical to power; the duty layers are not.

Cable assembly tariffs by HTS code

On 8544.42.90 the China figure is base + 25% Section 301 + 25% Section 232 copper; Vietnam is base + Section 232, since the List 3 Section 301 applies only to Chinese-origin goods. The 12.5% forced-labor duty appears on neither: HTSUS note 52(f)(1) excludes articles of copper provided for in 9903.82.09 from it. Mexico is the line to read twice — USMCA waives the base rate and both Section 301 layers, but note 16(b) collects the Section 232 duty in addition to any special free-trade rate, so a USMCA-qualifying assembly enters at 25.0%, not zero. Coax and fiber are absent from the copper list, so they keep the forced-labor layer, pay no copper duty, and still enter free from USMCA Mexico. For the full power stack alongside these codes, see the duty stack.

Why the codes now differ by more than the base rate

Until April 2026 the base rate was the only variable across the cable line. It no longer is — the copper list is.

• 8544.42.90 — 2.6% base, plus the copper duty. USB-C, USB, HDMI, DisplayPort, Ethernet patch, AV, and power cords — insulated conductors for ≤1,000 V, fitted with connectors. This is where most of a connectivity order classifies, and it is on the copper list.
• 8544.20.00 — 5.3% base, no copper duty. Coaxial cable and other coaxial conductors. The highest MFN base of the common cable codes, and now the cheaper entry: a coax reel from China lands at 42.8% against 52.6% for a terminated assembly.
• 8544.70.00 — Free, no copper duty. Optical fiber cables made up of individually sheathed fibers. No base rate and no metal content that counts, so the entire landed duty is the Section 301 overlay.

The 15% threshold

The copper duty is a fact about your part, not only about its code. HTSUS note 16(c) reaches the article only where the applicable metal is at least 15% of the weight of the imported good, aggregating copper and aluminium where a code appears on both lists — as 8544.42.90 does. A normal cable assembly clears it: the conductor is the heaviest thing in the box. An assembly that does not — a short lead dominated by moulded plastic and a die-cast shell — falls to 9903.82.03, pays no copper duty, and picks the 12.5% forced-labor duty back up, landing at 40.1% from China and 15.1% from Vietnam. If your product sits near the line, weigh the copper before you plan against either number, and confirm with your broker.

The same origin logic as power

Origin is set by substantial transformation, exactly as it is for a power supply. A cable assembly is Vietnamese if the transforming operations — drawing and stranding the conductor, extruding insulation, and molding and terminating the connectors — happen in Vietnam. Take finished Chinese cable and only mold a connector onto the end in Vietnam, and it is still Chinese; entering it as Vietnamese is transshipment, assessed the full Chinese-origin rate with every layer reinstated, plus penalties.

The documents that settle a cable assembly’s origin are the same four that settle a power supply’s — the checklist is in how to verify a Vietnam country of origin. To source USB-C, custom cable, and harness builds to your spec, see Connectivity.