write off phrasal verb ( see also ↑ write )
1 . to write a letter to a company or organization asking them to send you goods or information SYN send off , write away
write off for
Are you going to write off for that free poster?
2 . write somebody/something ↔ off to decide that someone or something is useless, unimportant, or a failure SYN dismiss
write somebody/something ↔ off as
After six months of work, we eventually wrote the project off as a non-starter.
⇨ ↑ write-off
3 . write something ↔ off to officially say that a debt no longer has to be paid, or officially accept that you cannot get back money you have spent or lost:
The United States agreed to write off debts worth billions of dollars.
The Inland Revenue wrote off £900 million in unpaid taxes.
4 . write something ↔ off to make an official record of the amount of money that you have spent on things relating to your business, in order to reduce the amount of tax that you have to pay
write something ↔ off against
The costs of setting up a business can be written off against tax.
5 . write something ↔ off British English to damage a vehicle so badly that it can never be used again:
At thirteen he stole a car and wrote it off.
⇨ ↑ write-off