You receive a quotation on 8 March. You place the order on 19 April at the same numbers. The factory says steel moved, the RMB moved, or that quote was “for reference.” You say they already sent a PI. Both of you are looking at a page that never said how long the numbers would last.
This piece is the validity line on the quote and on the PI — not a lecture on commodity prices.
1. A quotation and a PI are different clocks
A quotation is an offer. A signed PI is the deal. Write both dates:
- the quote is valid until a calendar date (or for X days from the date on the letterhead)
- the PI, once signed, locks the price for that PO — unless you also wrote a window to open the L/C or pay the deposit
If you sit on a quote until after its date, you are asking for a new quote, not enforcing an old one. If they issued a PI and you signed it inside the stated period, they do not get to reopen the unit price because a later WeChat message feels better.
2. What should expire with the date
Name what dies when the clock runs out: unit price, ship window, and any promised deduction of the sample fee. Do not leave “price subject to change” in the footer and a firm number in the table. Those two sentences cancel each other. Pick one.
If materials are volatile (copper, oriented steel, certain resins), a short validity — one or two weeks — is normal. A 90-day price on those items is either a gift or a sentence they will not honor. Match the length to the input, not to your internal approval cycle.
3. After they sign, add a deposit deadline
A PI with no “deposit by date Y or this PI lapses” lets you hold their capacity with a scan. They will then sell the slot and call your PI expired in spirit. Put a deposit-by date next to the validity date. If you miss it, you need a new PI — not an argument that last month’s scan is still live.
4. Reprint the date on every revision
Each revised PI should carry a new number and a new validity. Do not keep editing the same PDF until nobody knows which page was accepted. The version that both sides signed — date visible — is the one the inspector and the bank will be asked to follow.
The bottom line
Quotes expire. PIs lock a price only after they are signed, and only if you also say when the deposit must land. A number with no date is a suggestion. A signed page with no deposit deadline is a reservation you have not paid for.
If you need validity and deposit-deadline wording written into the quote or PI in English and Chinese, I can prepare the clause and issue a stamped set under our bilingual translation company seal when you need one. See what this covers.
Offer and acceptance rules depend on the governing law. This article is general sourcing guidance, not legal advice.