Getting a contract assembly quote shouldn't feel like guesswork. You need real numbers that account for your design complexity, volume, and timeline—not a placeholder figure that balloons once production starts. Here's how to request quotes that actually stick and let you compare apples to apples.
Start With a Complete Bill of Materials
Your BOM is everything. A contract assembler can't give you an accurate quote without knowing exactly what you're assembling—part numbers, quantities, sourcing (do they buy it or do you?), and any special handling requirements.
Include PCB specifications if relevant: layer count, trace width, surface finish. For mechanical assembly, specify materials, fastener grades, and finish requirements (anodizing, painting, plating). If components have long lead times, mention that upfront—it affects scheduling and sometimes pricing.
The more detail you provide, the fewer assumptions the manufacturer has to make. Vague BOMs lead to vague quotes, which lead to surprises later.
Define Your Volume and Production Timeline
Contract assemblers price differently at different volumes. A 500-unit run costs per-unit differently than 5,000 units. Most reputable shops will provide tiered pricing: tell them your volume expectations for year one, and ask for pricing at 25%, 50%, 75%, and 100% of that forecast if you're uncertain.
Timeline matters too. A 12-week lead time production run is cheaper than expedited 4-week turnaround. If you need 10,000 units in 8 weeks, you're paying for labor flexibility and potential overtime. Be realistic about what you actually need.
Ask About Setup, Tooling, and NRE Costs
Non-recurring engineering (NRE) and tooling fees are where surprises hide. A contract assembler might charge $500–$3,000 for setup depending on complexity, plus additional fees for custom fixtures or tooling.
When requesting a quote, explicitly ask for:
- Machine setup costs (per production run)
- Custom tooling or fixturing fees
- First article inspection (FAI) costs, if applicable
- Any engineering fees for design review or DFM (design for manufacturability) feedback
- Rework or scrap allowances
These should be listed separately from unit cost, not buried in a per-unit price that makes comparison impossible.
Specify Quality and Testing Requirements
Quality levels cost money. Stating "IPC Class 2" or "IPC Class 3" for electronics assembly changes the price. For mechanical assembly, tolerances matter: ±0.1mm is more expensive than ±0.5mm.
Also clarify testing expectations:
- In-circuit testing (ICT) for PCBs
- Functional testing
- Visual inspection standards
- Traceability and documentation requirements
- Any third-party certifications (UL, CE, RoHS compliance)
Ask the assembler what quality they include in their baseline quote and what costs extra.
Request References and Lead Time Confirmation
A low quote that gets pushed three months means nothing. Ask the potential provider:
- How many similar projects have they completed in the past 12 months?
- Can they reference a customer with comparable complexity and volume?
- What's their actual lead time from order to shipment (not their marketing promise)?
- What happens if components are delayed—do they hold inventory, or do you absorb the delay?
Talk to at least one reference if volume is significant. You're betting production timeline on their reliability.
Prepare for Comparison and Negotiation
Once you have three to five quotes, build a simple spreadsheet: unit cost, setup fees, tooling, timeline, and payment terms. Look for consistency. If one quote is 40% lower than others, ask why—it might be a calculation error, or they might be under-scoped on quality or testing.
Most contract assemblers have flexibility on pricing for committed volumes or repeat business. If you like a vendor but their quote is high, ask what volume would justify a 10–15% reduction, or what timeline flexibility could bring costs down.
Platforms like Mercoly let you request and compare quotes from multiple trusted contract assembly providers in one place, so you can focus on the numbers rather than hunting down suppliers individually.
Frequently Asked Questions
Q: How long does a typical contract assembly quote usually take to receive? Standard quotes take 3–7 business days if your documentation is complete; expedited quotes (24–48 hours) usually cost extra or come with less detail.
Q: Should I ask for a quote that includes component sourcing, or should I supply all parts myself? It depends on volume and expertise: most assemblers offer turnkey pricing (they source and manage inventory) at a markup, or consignment pricing if you supply parts, which is often 5–10% cheaper but requires you to manage lead times and quality.
Q: What's a realistic per-unit cost range for basic contract assembly? Simple manual assembly runs $1–$5 per unit depending on complexity; automated PCB assembly with testing ranges from $0.50–$3 per board; larger mechanical assemblies can run $10–$50+ per unit before tooling amortization.
Get your documentation tight, request detailed quotes from multiple providers, and compare total landed cost—not just unit price.