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Turnkey vs Consigned PCB Assembly (and Quick-Turn Options)
Turnkey PCB assembly, consigned and partial turnkey compared: who buys the parts, who carries the risk, what it costs, and when quick-turn pays off.
by the HardwareMap editors4 min read
Contents
Turnkey PCB assembly means the assembler sources every part and delivers finished boards; consigned means you buy the parts and ship them in; partial turnkey splits the two. The choice decides who carries parts risk, how much of your week goes to purchasing, and how fast a build can start. It sits under our PCB assembly guide.
Turnkey PCB assembly vs consigned vs partial turnkey
Vendors publish all three. PCBWay, for example, lists consigned/kitted, turnkey and partial turnkey/combo as its three parts-sourcing options, and describes the combo as its regular practice (PCBWay assembly capabilities).
When full turnkey wins
- You are small. A two-person team does not have a buyer. Turnkey turns 40 purchase orders into one.
- The BOM is standard. Common passives, popular MCUs and catalog connectors are what assemblers buy every day, often at better prices than a startup gets.
- You need speed. Parts ship to the assembler, not to you and then to the assembler. One shipping leg disappears.
Two things to require on a turnkey order. First, approve substitutions in writing: any part not matching your manufacturer part number should come back to you for sign-off. Second, ask for the components line itemized with supplier and quantity, including attrition extras, so you can see what you paid for.
When consigned or partial turnkey wins
- A part is scarce. If you hold the last allocation of a processor, ship it in. Do not ask an assembler to find more.
- You have pricing. If you negotiated volume pricing with a distributor or the manufacturer, that price usually stays with you, not the assembler.
- A part is controlled or custom. Pre-programmed chips, custom modules, export-controlled parts and parts tied to your supplier agreements are often easier to consign.
- You already hold stock. Leftover reels from a previous run are free parts.
Consigning has costs that do not show on the quote. Assemblers expect extra quantity of small parts to cover machine attrition, usually a few percent or a minimum number per reel. Parts should arrive on reels or cut tape long enough to load into a feeder, labeled with your part number. Loose parts in bags may be rejected or hand-placed at extra cost. A missing part stops the whole build.
Send a kit list with every shipment: your part number, manufacturer part number, quantity sent and reference designators. Count before you seal the box. Ask the assembler to confirm receipt against the list within a day, so a short count surfaces while you can still order more, not on the morning of the build.
Quick-turn PCB assembly: what you pay for speed
Quick-turn means a shorter queue, not a different process. Advertised quick-turn windows commonly run 1 to 5 business daysest for assembly once boards and parts are in hand, against 2 to 4 weeksest for standard production queues. The premium can be significant on small orders: 25% to 100% or moreest over a standard-lead quote is not unusual.
Pay it when the board is on the critical path: a bring-up that blocks firmware, a demo with a date, a customer pilot waiting on hardware. Do not pay it to compensate for parts you have not bought. If a part is out of stock, quick-turn assembly does not help, and a turnkey assembler can only wait for it like everyone else. Check stock before choosing the tier, and see PCB assembly cost for how lead time shows up on the quote.
How to compare turnkey PCB assembly quotes
Turnkey quotes from different vendors rarely line up line for line. Normalize them before you choose:
- Same data package. Send identical Gerbers, BOM, centroid and quantity to every vendor. A quote on a different revision is not a comparison.
- Parts priced per line. Ask each vendor to show unit price, quantity bought (including extras) and supplier for every BOM line. Totals hide where the money goes.
- Substitution policy. Does the vendor substitute without asking, ask per part, or refuse to substitute? Get it in writing.
- Excess parts. Minimum order quantities mean the vendor may buy a full reel for 20 placements. Ask who owns the leftovers and whether they ship back.
- What is included. Stencil, setup, AOI, X-ray, functional test, packaging. One vendor's low number may exclude what another includes.
- Lead time on the slowest part. The quoted turnaround means nothing if one part has a long lead time. Ask which line sets the date.
Put the results in one table with landed cost per good board as the bottom row. The cheapest line total is not always the cheapest board.
A practical default for startups
For a first prototype, full turnkey from an online service is the fastest route with the least overhead. See prototype PCB assembly for the options. As the product firms up, move to partial turnkey: consign the few parts that are expensive, scarce or allocated to you, and let the assembler buy commodity parts. At production volume, the decision moves to your electronics contract manufacturer and its purchasing team, and the question becomes who owns inventory risk, which belongs in the contract.
Whatever the model, keep one source of truth: a BOM with manufacturer part numbers, approved alternates and a clear do-not-populate column. Our bill of materials example shows the format.
Frequently asked questions
What is turnkey PCB assembly?
Turnkey PCB assembly means the assembler handles everything: it fabricates or buys the bare boards, sources every component on your bill of materials, assembles and inspects the boards, and ships finished assemblies. You send design files and a BOM, approve the quote and any substitutions, and receive working boards. It trades some control over parts sourcing for far less of your time.
What is consigned PCB assembly?
Consigned, or kitted, PCB assembly means you buy the components and ship them to the assembler, which only provides labor, process and inspection. You control part choice, lot and price, and you carry the risk of shortages and kitting errors. It suits teams that already hold inventory, have negotiated pricing, or use parts the assembler cannot buy.
Is turnkey PCB assembly more expensive than consigned?
Not always. Turnkey quotes include parts, and some assemblers add a handling margin while others say they do not mark parts up. Consigned quotes look cheaper but leave out your time spent buying, kitting, counting and shipping, plus extra parts for machine attrition. Compare the total cost including your own hours and the cost of a build delayed by a missing part.
What is partial turnkey PCB assembly?
Partial turnkey, also called combo, splits sourcing. You supply the parts that are expensive, scarce, controlled or already in your stock, such as a processor or a radio module. The assembler buys the rest, usually passives and common parts. It is the most common arrangement for startups that have a few critical components and many commodity ones.
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