In most categories the price decides whether an order happens. In electronics the certificate does. A product that cannot be authorised for your market is not a cheaper product — it is a container you cannot clear, sitting at a port, accruing storage.
That inversion is the single most useful thing to understand before you start. Factory quotations for electronics are often genuinely low, and the reason is frequently that the quoted build does not carry the approvals your market requires.
Where electronics are made, and why that matters
Shenzhen and the surrounding Pearl River Delta hold the densest electronics supply chain in the world. That density is the advantage: a component that would take six weeks to source elsewhere is available the same afternoon, and a design change can be prototyped in days rather than months.
It is also the risk. The same density means a "factory" may be an assembly house with no design capability, buying boards from one supplier, enclosures from another and batteries from a third. Nothing is wrong with that model — much of the industry runs on it — but it determines who is accountable when a batch fails, and whether anyone can tell you why.
A practical test: ask who owns the bill of materials, and ask to see it. A factory that designs and controls its own BOM will show you one. An assembly house will tell you it is the customer's, or the designer's, or that it varies.
The certificate is for one model, not a family
The most expensive misunderstanding in this category is treating a certificate as a property of the supplier rather than of a specific product configuration. A test report belongs to a particular design, with particular components, tested at a particular laboratory.
So when a supplier sends a certificate for "the same model", read the model number, the date, the laboratory and the scope. If your unit has a different power supply, a different radio module, a different enclosure material or a different battery, the report may not cover it. The factory is not necessarily being dishonest — in its own framing, it really is the same product. Your customs authority does not share that framing.
Where the cost quietly moves
Component substitution. This is the defining risk of electronics sourcing. A capacitor, a MOSFET or a driver IC is substituted for a cheaper equivalent between the sample and the production run. The unit still works on the bench. It fails at eighteen months, in your customer's hands, at scale. Locking the BOM in writing and inspecting against it is the only defence.
Wire that is not what it says. Copper-clad aluminium is sold as copper across several categories — power cords, adapters, lighting. It is cheaper, it is lighter, it has higher resistance, and in a power product that means heat. Specifying conductor material and cross-section, then verifying it, is cheap. Discovering it after a recall is not.
Lithium cells. Any product with a lithium battery needs UN38.3 transport testing before it can legally ship by sea or air, and it moves as dangerous goods. That changes the freight quote, the paperwork and sometimes the forwarder. Buyers routinely discover this after the goods are made.
Tooling. An injection mould for an enclosure is a real capital cost, usually paid before production. Who owns the tool, where it is stored and whether you can move it to another factory should be agreed in writing before you pay for it — not after the relationship sours.
Approvals, by market
For the United States, a device that intentionally or unintentionally emits radio frequency energy needs equipment authorisation from the FCC, through either Certification or a Supplier's Declaration of Conformity depending on the device class. Mains-powered products are normally expected to carry a recognised safety mark such as UL or ETL — not legally mandatory in every case, but commercially mandatory for most retail and insurance purposes. Products intended for children bring the Consumer Product Safety Commission into scope.
For the European Union, CE marking covers the applicable directives — typically EMC, Low Voltage, Radio Equipment and RoHS — with a Declaration of Conformity and a technical file the importer must be able to produce. For Great Britain, CE marking is recognised indefinitely across the regimes that matter here — electromagnetic compatibility, radio equipment, low voltage and RoHS — so a product that already carries CE does not need a separate UKCA mark. Northern Ireland requires CE. WEEE and battery regulations add producer registration obligations in the destination country, which fall on you, not on the factory.
None of this is exotic, and a good factory has done it many times. The failure mode is not usually inability; it is a quotation built on the assumption that you would not ask.
What we do on an electronics order
Establish whether the supplier designs or only assembles, get the bill of materials in writing and keep the production build locked to it, read the actual test reports rather than accepting a certificate photograph, confirm battery transport documentation before freight is booked, agree tooling ownership before any tooling payment, and inspect against the BOM rather than against appearance. Our fee is stated separately from the factory invoice and we never take title to your goods.
