Send an RFQ to too few suppliers and you're not really testing the market — you're just checking whether your usual two vendors are still competitive with each other. Send it to too many and you're burning goodwill: suppliers who spend time pricing a job they never had a real shot at start deprioritizing your RFQs over time, because they've learned the odds aren't good. Both mistakes are common, and the right number depends on the job, not a fixed rule.
The default: three
For a routine, price-competitive job, three suppliers is the practical sweet spot. It's enough to establish a real range — if two quotes are close and one's an outlier, you know which one to question — without spreading the same job across so many vendors that most of them are quoting purely as a courtesy with no real chance of winning.
When to send fewer
Highly specialized work. If only two or three suppliers in your network can actually do a given process — a specific plating spec, a tight tolerance only certain shops hold reliably — sending it wider just adds noise. Send it to who can actually do it.
Strategic or relationship-sensitive jobs. If you're sourcing from a supplier you're deliberately trying to grow the relationship with, RFQ comparison-shopping every job undercuts that. Some purchases are about partnership, not just price.
Time-critical jobs. Every additional supplier adds a small amount of coordination overhead — one more party to follow up with, one more quote to wait on before you can compare. If the deadline is tight, narrowing the list to your most reliable, fastest-responding suppliers gets you a decision faster, even if it's a slightly less exhaustive comparison.
When to send wider
New categories of spend. If you don't have an established supplier base for a given part type yet, cast wider — four or five — to build real market knowledge and start identifying who's actually competitive before narrowing to a regular short list.
High-volume or high-value jobs. The bigger the job, the more a percentage point of price difference is worth in absolute dollars, which justifies the extra coordination cost of a wider comparison.
The mistake that costs you long-term, not just this RFQ
Sending every job to every supplier in your network, regardless of fit, is the version of "wider is safer" that backfires. Suppliers notice when they're consistently quoting jobs they have no real shot at winning, and the ones with other business to prioritize will start responding slower — or not at all — to RFQs from a buyer whose hit rate with them is low. Matching the RFQ list to who's actually competitive for that specific job protects response quality on the RFQs that matter.
Knowing who's actually competitive for a given job type is easier when you can see win rate by supplier, not just gut feel. RFQTrace tracks that automatically as a byproduct of running your RFQs through it. Start a free 60-day pilot and let a few months of real data tell you who belongs on which RFQ.