From Longman Dictionary of Contemporary Englishtrade something ↔ in phrasal verbEXCHANGEto give something such as a car to the person you are buying a new one from, as part of the payment forHe traded his old car in for a new model. →trade-in →trade→ See Verb table
trade-inˈtrade-in noun [countable]American EnglishBBTSELL a used car, piece of equipment etc that you give to a seller of a new one that you are buying as part of the payment syn part exchange British EnglishAre you going to give your Ford as a trade-in?trade-in price/valueThe trade-in value is roughly $3,000.
Examples from the Corpus
trade-in• Your old computer isn't going to be worth much as a trade-in.• You negotiate the price of the model you want and pay a deposit either by cash or as a trade-in.• Next came mortgage buy-downs, trade-ins of existing homes and extralandscaping.• Nothing unusual in that, except that his trade-in was an S-class Merc.trade-in price/value• This may be the trade-in price of your existing car which means you won't have to dip into your savings.• Sellers may negotiate price, creditterms, deliverytimes, trade-in values and other aspects of the commercialtransaction.From Longman Business Dictionarytrade something ↔ in phrasal verb [transitive]to give something, such as a car, as part of the payment for something you are buyingThe Toyota dealer only offered him $4,000 to trade it in. → see alsotrade-in →trade→ See Verb tabletrade-inˈtrade-in noun [countable, uncountable] American EnglishCOMMERCEa way of buying a new car, computer etc in which you give the seller your old car etc as part of the payment SYN PART EXCHANGE BrEA dealer may accept old equipment as a trade-in on a new computer.They can’t afford a new car because thetrade-in value of the old one has dropped so much.