The bill of materials you send decides the quote you get
A quotation is only as good as the information behind it. When an enquiry is ambiguous, a supplier has two options: ask, or guess. Asking costs a day. Guessing costs a rework, or a wrong part on your line. Neither is what you want, and both are avoidable at the point where you prepare the file.
The six things a quotable line needs
- Reference designator — the line position (R14, U3, C22). It is how you and the supplier refer to the same row later, and it removes any doubt when a description is imperfect.
- Manufacturer part number — the complete ordering code, including every suffix. This is the single most common cause of quoting delay. A base number without its suffix can map to several parts, with different packages, tolerances, grades and prices.
- Manufacturer — so the correct part is identified even if the number is mistyped or written in a house format.
- Quantity per assembly and the build volume you are planning. Unit price depends on quantity, so a line without a quantity cannot be priced at all — and the planned annual volume often unlocks a better band than the immediate order suggests.
- Substitution permission — state it explicitly. See below; this one field changes the entire sourcing strategy.
- Required date — and whether it is firm or a target. A firm date and a flexible one are sourced differently.
Substitution permission is the highest-value field
Decide which of these applies, per line, and write it down:
- No substitutes. The exact ordering code only. Use this where the part is qualified, certified, or where firmware and timing depend on it.
- Same manufacturer, equivalent allowed. A middle ground that keeps the die and family intact while allowing a different package, grade or packing suffix.
- Cross-manufacturer equivalents acceptable. Widest sourcing reach and usually the fastest route out of a shortage — but it requires a real technical comparison, not a catalogue match.
Leaving this blank does not mean "at your discretion". In practice it means the supplier will quote exactly what you wrote, miss the opportunity to offer an alternative, and both sides wait longer. If you want options, ask for options — and if you want them, ask for the comparison alongside the price so you can judge it. Our guide to finding a safe alternative to an obsolete part covers what that comparison must include.
Formats that work
A spreadsheet is fine. What matters is that the columns are machine-readable and consistent:
- One row per ordered part, with repeated designators listed together (R1, R2, R9) rather than duplicated as separate rows
- Part numbers as text, not reformatted by the spreadsheet — leading zeros and trailing characters are meaningful
- A separate column for notes, never inside the part number field
- No merged cells, and no colour as the only carrier of meaning
If your BOM comes from a design tool, sending the native export is usually better than a reformatted printout.
What a useful quote looks like coming back
When the enquiry is complete, the reply can be complete too:
- Line-by-line confirmation of the exact ordering code offered
- Unit price with its quantity band stated, so you can compare like with like
- Stock versus factory lead time, quoted as separate figures
- Packaging format, and any rounding to packaging multiples
- Alternatives, where you allowed them, with the difference that matters
- Any line that could not be sourced, stated plainly rather than omitted
Sequencing a multi-line BOM
Large BOMs are rarely sourced in one pass, and trying to force it delays everything. A workable order:
- Send the complete BOM, so the whole requirement is visible and can be priced together.
- Flag the long-lead and hard-to-find lines explicitly — those decide the schedule.
- Confirm the exact ordering codes on those lines first.
- Let the commodity lines be filled around them.
Common causes of a slow quote
- Base part numbers with the suffix omitted
- Quantities in the wrong unit — pieces versus reels, or per-board versus total build
- Substitution permission left blank in both directions
- Notes embedded in the part number column
- A required date that is firm but not stated as firm
- Descriptions copied from a distributor search result rather than from the design file
Sending a BOM
At YILUDA TECH every listed part is 100% original, new and unused, with no refurbished or counterfeit material, held in stock at our Shenzhen warehouse and shipped worldwide by DHL, FedEx or UPS.
Send your BOM through our contact page with the destination and required date, and we will confirm availability, pricing and lead time line by line. If you are still specifying, our guides to MOQ, price breaks and lead time and to packaging formats cover the two fields most often left out. You can also browse the full component inventory.