A write-off in terms of debt refers to reducing the value of something. It can be used in the financial world as a reduction in a loan amount for example "The bank issued a debt write-off on a loan" It can be used in a personal financial capacity such as "Somebody hit my car and its totally wrote-off / its a write-off" meaning the car has less or no value anymore. To write to someone, it would be better to use "sent" or "wrote to" Examples: "I sent a letter to the TV advert to avail of an offer" "I wrote to my idol's fan mail address for an autograph" M