How to write a wire harness RFQ

A good wire harness RFQ gets you accurate, comparable quotes on the first pass. Incomplete requests force suppliers to guess or come back with questions, which delays quoting and inflates prices to cover the unknowns. Use this checklist to send everything a manufacturer needs.

What to include in a wire harness RFQ

• Drawing and BOM — a dimensioned harness drawing or wiring diagram plus a bill of materials, ideally with approved manufacturer part numbers.
• Wire specification — gauge (AWG/mm²), insulation type and rating, colour code and any shielding or twisting requirements.
• Connectors and terminals — exact part numbers for connectors, terminals, seals and backshells, and whether substitutes are acceptable.
• Quantities — prototype quantity, estimated annual usage (EAU) and any batch or release schedule; volume drives price more than any other single factor.
• Quality requirements — required certifications (IATF 16949, ISO 13485, AS9100), IPC/WHMA-A-620 class, test requirements (continuity, hipot, functional) and PPAP/first-article expectations.
• Packaging and labelling — how assemblies should be bagged, boxed, labelled and shipped.
• Timeline — needed sample date and production start, so suppliers can flag lead-time or tooling constraints up front.

Common RFQ mistakes

The usual gaps are missing connector part numbers, no EAU (so suppliers can't price volume), unstated test requirements, and no target date. Any one of these turns a firm quote into an estimate.

Send one RFQ to several suppliers

Quotes are only comparable when every supplier gets the same package. Shortlist plants that fit your part on Harness Atlas and send a single RFQ to several at once, with tracked open and reply status. New to supplier selection? Start with how to choose a wire harness manufacturer.