Electronics accessories are the category most often quoted as "we can do that in ASEAN" and most often mishandled, because the assembly can move long before the component supply does.
What is genuinely regional
Enclosure moulding, cable assembly, wire harness, final assembly, packaging and test are well established in Thailand, Vietnam and Malaysia. Malaysia and Thailand carry the deeper EMS base; Vietnam is strong on labour-intensive assembly.
What still comes from elsewhere
Silicon, most passives, connectors and many magnetics are still sourced from China, Taiwan or Korea. That is not a failure of the ASEAN factory — it is the global BOM. It matters for two reasons: origin rules for duty preference, and exposure if a component line stops.
Certification is the gate, not the factory
For a first-world market, the accessory needs the right marking before it needs a price: FCC and UL/ETL for the US, UKCA/CE with EMC and LVD for the UK and EU, RCM for Australia. Battery-containing products add UN38.3 and shipping classification. Ask which lab the factory has used before and for a previous report on a comparable product.
BOM control
Approve the bill of materials by part number, not by description. "1A USB-C connector" is not a specification. Component substitution without notice is the single most common cause of a product that passed sampling and fails in the field.
Tooling and second sourcing
Enclosure tooling is the main upfront cost. Own it in writing, take delivery of the tool drawing, and confirm the tool can be transferred. A second assembler on the same tool is cheap insurance once volume justifies it.
How we run it
TUSKO qualifies the assembler, freezes the BOM, holds certification evidence per model, and inspects each lot against functional test criteria — not just cosmetic AQL.