貿易往來中，買家總是覺得價錢太高，賣家總是覺得自己的價錢合理、再低就虧了。在這種情況下，談判、爭論、討價還價不可避免。
討價還價信也是說服信的一種，這種討價還價信的目的是使雙方達成一致、做成買賣。為了更多的為己方爭得利益，寫信的時候一定要強調己方反對對方要求價格的原因，并要提出雙方都能接受的條件。
寫討價還價信應遵循下面的原則：
1. Thank-you expression for what the reader has done.
2. State reasons for
non-acceptance and inability to take the desired action.
3. Make a
counteroffer or suggest that there may be other opportunities to do business
together.
4. Mention the possible benefits associated with the reader's
concession and encourage him to take action.
5. Close the letter courteously
and positively.
下面是一封要求對方降低價格的信，我們來看看是怎么寫的：
Dear Sirs
We write to thank you for your quotation of 20th March and the samples of the
LTZ Trimming Edge Cutters you enclosed.
Having carefully examined the samples you mailed, we feel quite satisfied
with the quality of your goods and the way in which you have handled our
inquiry. It would be profitable for both sides if a long-term business
relationship could be established
However, our marketing research reveals that the prices you quoted appear to
be on the high side even for tools of your quality. Goods of similar quality
which are sold at the prevailing levels are three percent cheaper than yours.
Some of our clients feel worried that accepting such an offer would only leave
them with a small margin of profit on their sales.
May we suggest that you perhaps make some allowance, say, two percent off
your quoted prices? We feel confident that the revised ones would help introduce
your products into our local markets. And you could also rely on large volume of
orders from us if our customers see increasing benefits from their deals.
Please kindly inform us of your decision as soon as possible because we need
your information to work out our import schedule by the end of this month.
Yours faithfully
（例文來源：《國際商務寫作教程》，對外經濟貿易大學出版社 英語點津 Annabel 編輯）
