Buyer accepts offer and signs it, where offer acceptance is binding depends of the legal jurisdiction. For example English and common law differs slightly from American uniform commercial law on matters of offer acceptance and when performance becomes binding on an offer. The seller can also reply with a pro forma invoice. In fact a pro forma invoice can serve as quote and offer, becoming a more or less binding purchase order upon buyer acceptance and signing. Pro formas are used more in smaller FCL trades, and not in larger bulk trades.
Contrary to the sellers' and their super sales_conscious agents' familiar claim that "There is nothing to lose in signing those documents," quite the complete opposite is true _ namely, a great deal, in fact, could potentially be lost particularly by the buyer by signing an LOI to a supposed seller. Why? In a word, this is because the LOI is actually fraught with many incalculable legal flaws, traps and pitfalls, much of which could often be prohibitively costly for the buyer, according to legal authorities and contract law experts. (See below for more on this)