Who buys the parts for a first production run, and which ones have to be made for you?

Who buys the parts depends on the deal. In turnkey assembly, the assembler buys every part, chases shortages and checks parts on arrival. In consigned assembly, you buy the parts and ship them in, and carry those risks yourself. Partial turnkey splits the list. For a finished product, this covers more than the board: someone also buys the custom parts made to your drawing, such as the molded case, cables, a battery pack, cover glass, labels and the printed box, and those usually set the schedule, because each needs a drawing, sample approval and sometimes tooling or a test of its own. Off-the-shelf parts, such as chips, connectors and screws, come from distributors. Modules, such as a radio module or a power adapter, are bought finished but come with certification and integration conditions you have to follow. Minimum buys and non-cancelable orders decide how much cash is tied up before the first unit ships.

Which parts are which, and who buys them?

Part type	Examples	Who usually buys	What it needs	Watch for
Off-the-shelf electronic parts	Chips, resistors, connectors, switches	The board assembler (turnkey) or you (consigned)	Manufacturer part numbers and approved alternates on the bill of materials (BOM)	Reel and package minimums on less common parts, long lead times, end of life, parts from unauthorized sellers
Mechanical hardware	Screws, threaded inserts, standoffs, foam, adhesive pads	The final assembler	A part number, or a drawing for anything non-standard	A missing small part stops the line as surely as a missing chip
Modules	A Bluetooth or Wi-Fi module with FCC approval, a power adapter	The assembler or you	The module maker's integration conditions; for an adapter, a safety listing and US efficiency compliance	The product still needs its own testing and labels
Custom electrical parts	Cables and wire harnesses, battery packs, displays	You or the final assembler, from a specialist maker	A drawing or specification, samples, approval; a transport test for every battery pack design	Lead times of months for battery packs; maker minimums
Custom mechanical parts	The molded case, machined or sheet-metal parts, cover glass, magnets	You or the final assembler, from a molder or a machine shop	A drawing with tolerances, a cosmetic standard, tooling, a first-article report	Who owns the tooling; rounds of samples
Printed parts and packaging	Labels, the retail box, inserts, the manual	You, or the final assembler through a printer	Artwork, dielines, proofs, regulatory marks	Print minimums; late artwork holds up shipping

A general rule: use a stock part wherever one fits. Each custom part adds a drawing, samples, a minimum order and weeks to the schedule.

Turnkey vs consigned assembly: who buys the parts?

Turnkey. The assembler buys every part on the list, chases shortages, proposes substitutes for you to approve, inspects parts on arrival and handles rejects with the distributor. It warrants its own workmanship and that it bought from approved sources; for a part that fails later, most agreements pass on only the part maker's warranty. You place one order with one supplier, but the schedule hit from a shortage and the bill for leftover parts still land on you. The assembler adds a markup to the parts it buys, so ask for the parts cost and the markup on separate lines. For a first run of a few hundred to a few thousand units, turnkey is the usual choice.

Consigned. You buy the parts and ship them to the assembler as a kit. The labor price looks lower, but you carry the risks the assembler would have carried: a kit one part short stops the line, moisture-sensitive chips need careful handling in transit, and a part bought from the wrong seller is your problem. When a board fails, it can be hard to say whether the part or the soldering was at fault. A kit has to arrive ready for the machines: parts on reels or cut tape with enough leader, fine-pitch chips in trays, moisture-sensitive parts in sealed bags with humidity cards, every bag labeled with the part number and quantity, and a few percent extra on each line to cover parts lost on the machines. Ask for the assembler's kitting specification, and agree how your stock is counted, stored and insured while it sits there.

If the assembler is in another country, a consigned kit also has to clear customs there, which can hold it for weeks and may cost duty or VAT unless the factory runs a bonded setup. And when the finished goods come into the US, the value of the parts you sent, plus the freight to get them to the factory, is added to the customs value. Consigning makes sense when you already hold the parts, or when a few unique parts are easier for you to buy.

Partial turnkey. You supply a few parts, often long-lead chips or parts you already bought, and the assembler buys the rest. Write down who chases a shortage of the parts you supply and who pays when the line waits for them.

For a finished product, the question goes beyond the board. Someone also buys the cables, the battery, the display, the glass, the labels and the packaging, and someone approves their samples. Agree which of these the final assembler buys, which you buy and ship in, and who checks them when they arrive. Buying a custom part yourself makes sense when it has the longest lead time or you want your own relationship with its maker; letting the assembler buy it makes sense when it already works with a supplier for that part and you want one party to answer for it.

Off-the-shelf parts: where should they come from?

Authorized distributors and brokers. Authorized (franchised) distributors sell parts straight from the manufacturer, with traceability and the manufacturer's warranty. Brokers fill gaps during shortages or for parts no longer made, but counterfeit and refurbished parts circulate in that market. Put the rule in your agreement: authorized sources by default, broker parts only with your written approval and testing, and a statement of who pays for the testing.
Reels and minimum package quantities. Common resistors and capacitors often come from the assembler's own stock or on cut tape. Some less common or pricier parts are sold only by the reel or in a minimum package, and the assembler may bill the whole package to your run. Ask which parts these are.
Attrition. Assemblers order a little more than the BOM calls for, to cover parts lost on the machines.
Lead times and shortages. Some parts take months to arrive, and in the 2021–22 chip shortage many parts took a year or more. Find the longest-lead parts early and order them first.
End of life. Parts go out of production. Check each critical part's lifecycle status before you design it in, and sign up for end-of-life notices on critical parts yourself, because neither the distributor nor the assembler always passes them on. When a part is discontinued, you usually get one last chance to buy it (a last-time buy).
Approved alternates, and what to do when there isn't one. Give parts an approved alternate on the BOM before production. The parts most likely to stop a run, such as the microcontroller, the radio module, the display and the power chip, often have no drop-in alternate; for those, buy early or hold a buffer of stock.

Does a product with an FCC-approved module still need testing?

Radio modules. A Bluetooth or Wi-Fi module that already holds FCC approval saves most of the radio testing, if you use it exactly as its approval allows, but the finished product still needs its own FCC emissions testing as a digital device (Part 15 Subpart B). Check whether the module's approval is full or limited, use only an antenna its approval covers, and check whether a handheld or body-worn product needs an RF exposure review. If the module's FCC ID isn't visible once it's inside, the product's label must say it contains the module, for example "Contains FCC ID: …".
Bluetooth listing. To sell a Bluetooth product, and use the Bluetooth name or logo, your company also has to declare it with the Bluetooth SIG, even with a module that's already qualified. As of March 2026, the fee is about $12,000 per design at the free membership level. Check the current fee schedule early.
Power adapters. If the product ships with a wall adapter, buy one that already carries a safety listing and meets US efficiency rules, rather than having one made. The adapter's listing doesn't cover the product it powers.

Which parts have to be custom made, and what does each need?

Battery packs. Every lithium battery pack design needs its own UN 38.3 transport test, even when its cells have passed theirs, and retailers often ask for a safety report such as IEC 62133. A custom pack can take months from specification to production, and the transport test alone takes weeks and a set of sample packs. Order it first. Batteries shipped on their own, not inside a product, are regulated dangerous goods (UN3480): by air they can only go on cargo aircraft at a limited charge, with a dangerous-goods declaration, and the forwarder will want the UN 38.3 test summary and the safety data sheet.
Cables and wire harnesses. A drawing with the wire gauge, lengths, connector part numbers, pin-out and labels; a first-article sample to approve; a continuity test on every cable. Cable makers have minimums, so a stock cable often beats a custom one at low volume.
Displays and cover glass. Stock display panels come with minimums and can be discontinued, so ask how long the panel will stay in production. Custom cover glass needs a drawing of the shape, thickness, printed border, coatings and holes, plus sample approval.
Magnets. The grade, coating, tolerance and polarity marking go on the drawing. Strong magnets have rules for air shipping.
Labels. The rating and regulatory label needs artwork, a material that passes the safety standard's durability tests (UL 969 covers label durability), and a serial number or barcode format.
Printed packaging. The box, insert and manual need dielines (the cutting and folding layout), artwork and color proofs, and printers have minimums. Drop-test the packed product before the run, to an ISTA procedure or your retailer's own test.
Molded, machined and sheet-metal parts. A drawing with critical dimensions and tolerances, a cosmetic standard, tooling and a first-article inspection report (a full check of the first parts against the drawing). Molding is covered in Moving from a 3D-printed prototype to injection molding, and the choice of process in 100 to 1,000 units: bridge tooling, urethane casting or machining?.

Minimums, non-cancelable orders and leftover parts: who pays?

Leftover parts come from minimum buys, full reels, custom parts made in minimum runs, non-cancelable non-returnable (NCNR) orders, design changes that strand old parts, and last-time buys of parts going out of production. Most contract manufacturing agreements make you pay for leftovers caused by the minimums and NCNR parts listed on the costed BOM, the priced parts list the quote is based on. Some suppliers bill them up front, some after the run, and some fold them into the unit price, where you can't see them.

Ask the supplier to list in the quote which parts are non-cancelable, what the minimums are, and how leftovers are billed or sold off. Agree in writing that the assembler buys only against your firm orders, plus the long-lead or NCNR parts you approve by name, and that you're liable only for those. Agree where paid-for leftovers go, shipped to you or held for the next run, and for how long. Plan when a design change takes effect, so old stock gets used up. That is cash you pay before, or soon after, the first unit ships, so count it in the cost of the run, as in What's actually in a production quote.

Example: the parts for 1,000 Bluetooth desk devices

This is an illustration, not a customer project.

A team is making 1,000 units of a desk device with a two-part molded case, one board, a Bluetooth module, a small display, a rechargeable battery pack, a USB-C cable and a printed box.

Board parts. The board assembler buys them, turnkey. The BOM lists an approved alternate where one exists; for the microcontroller, which has none, the team approves an early buy. The quote names the parts bought by the full reel and how leftovers are billed.
Bluetooth module. The board assembler buys it with the other board parts. It already holds FCC approval, the team follows the maker's antenna rules, and the label reads "Contains FCC ID: …". The device still goes through its own emissions test, and the team budgets for the Bluetooth SIG declaration.
Display. The final assembler buys a stock panel. The supplier confirms in writing how long it will stay in production, and the team picks a second panel with the same outline and connector that the firmware already supports, and tries it on a few units.
Battery pack. The team buys it from a pack maker that builds it from its standard cells and tests this pack design to UN 38.3. It's ordered first because it has the longest lead time, and buying it directly lets the team manage the pack maker's minimum and test samples itself. The pack maker ships it straight to the final assembler under the dangerous-goods rules, and the final assembler checks each lot on arrival. This makes it a partial-turnkey split, so the agreement says who pays if a pack fails final test.
Cable. The final assembler buys a stock USB-C cable instead of a custom one, so there's no cable minimum.
Case. The final assembler orders it from a molder, using aluminum molds the team owns.
Box and labels. The team supplies the artwork and the final assembler buys the printing. Artwork starts when the molds are ordered, not after the first samples, so printing doesn't hold up the first shipment.

Where we come in

This is one of the situations Anamor takes on. We start from your parts list and line up the board assembly, the molded, machined and sheet-metal parts, and final assembly.

Anamor takes US hardware teams with a working prototype into their first production run: we redesign the product for production, line up partner factories and suppliers in the US and overseas, price it at your quantities, and run the build through to shipping.

Send what you have: photos of the prototype, CAD if you have it, the parts list, and how many you plan to make. Need an NDA? We'll send our mutual NDA, or review yours, before you send files. Within two business days, a real person on our team will reply with a free first look at your production run and a few times to talk.

Frequently asked questions

What's the difference between turnkey and consigned assembly?

In turnkey assembly, the assembler buys every part, chases shortages and inspects parts on arrival, adding a markup to the parts it buys. In consigned assembly, you buy the parts, ship them in as a kit and carry those risks. Partial turnkey splits the list. For a first run of a few hundred to a few thousand units, turnkey is the usual choice.

If I use an FCC-approved Bluetooth module, does my product still need FCC testing?

Yes. A module that already holds FCC approval saves most of the radio testing if you use it exactly as its approval allows, but the finished product still needs its own FCC emissions testing as a digital device (Part 15 Subpart B). If the module's FCC ID isn't visible, the label must say "Contains FCC ID: …".

Does a custom battery pack need its own UN 38.3 test?

Yes. Every lithium battery pack design needs its own UN 38.3 transport test, even when its cells have passed theirs, and retailers often ask for a safety report such as IEC 62133. A custom pack can take months from specification to production, so order it first. Batteries shipped on their own are regulated dangerous goods.

Who pays for leftover parts from minimum buys and NCNR orders?

Usually you do. Most contract manufacturing agreements make you pay for leftovers caused by the minimums and non-cancelable, non-returnable (NCNR) parts listed on the costed BOM. Agree in writing that the assembler buys only against your firm orders plus the parts you approve by name, and that you're liable only for those.