ORIGIN

Origin is a legal test. We manufacture both answers.

Country of origin is not where a carton is sealed. It is where the article was substantially transformed — a test CBP applies part by part, process by process. Kestner builds the same power supplies in Vietnam and in China, and enters the origin you elect at its true rate.

What country of origin legally is

Under 19 CFR Part 177, an article originates where it acquires a new name, character, or use. CBP's substantial-transformation analysis for power supplies turns on where the transformer is wound, the board is populated, and the unit is programmed — not where the box is packed, and not what the carton claims.

Transshipment — Chinese goods relabeled through a third country — carries a 40% penalty rate. The buyer's protection is an importer of record with its own analysis on file. That is what Kestner is, whichever origin you elect.

Two plants, one engineering system

Our family has manufactured switching power supplies since 2005 — first in Jiangsu, China, and since 2018 in Vinh Phuc, Vietnam. The plants share one drawing set, one test procedure, and one engineering team. The same part number builds in either; the origin entered is your election on the purchase order, not a requalification.

JIANGSU, CHINASINCE 2005
Winding, SMT, final assembly, and test under one roof.
Entered as CN · effective duty today 35.0%
VINH PHUC, VIETNAMSINCE 2018
Winding, SMT, final assembly, and test under one roof.
Entered as VN · effective duty today 10.0%

Both lines are offered openly at their entered rate. When the tariff schedule moves, volume moves between them — same drawings, same UL file, nothing to requalify and nothing to explain to your customer.

The worked example: Vinh Phuc

Vietnam is the origin most buyers elect at today's rates. This is the line that earns it.

[ PHOTO 1 — production line, Vinh Phuc. Full bleed, uncropped, no grading. ]
[ PHOTO 2 — Shangye Li on the line. Not a headshot. Not a suit. ]

The plant at Vinh Phuc has produced switching power supplies since 2018 — winding, SMT, final assembly, and test under one roof. Shangye Li, principal of Kestner Supply, has sold its output for as long as it has run. Buyers audit the line by appointment; we do not charge for the visit and we do not stage it.

The file you receive with every entry

CBP Form 7501Entry summary as filed, showing HTS classification, declared origin, and duty paid — not estimated.
Certificate of originIssued per shipment — VCCI for Vietnam entries, CCPIT for China — referencing the commercial invoice and bill of lading numbers.
Mill certificatesFor magnetics, enclosures, and copper — the inputs a transshipper cannot paper over.
Test reportsUL 62368-1 file number, DoE Level VI efficiency data, FCC Part 15 report — plain text, verifiable at the source.

What the election is worth

Duty on HTS 8504.40.85 by country of origin, as entered. Both origins are on offer at these rates; today, Vietnam is the better answer by 25 points.

CHINAMFN 0%§301 25%§122 10%35.0%
VIETNAMMFN 0%§122 10%10.0%
DELTA  25.0 pts

Verified . Authorities and per-HTS figures on the duty stack page.

Rates verified [DATE] against HTSUS Rev. [N]. Not customs or legal advice.