Русско-англо-русский юридический словарь

If someone writes off a debt or an amount of money that has been spent on a project, they accept that they are never going to get the money back.

The committee decided to write off this debt. (COBUILD Advanced English Dictionary)

If you are unable to pay your debts, you should contact your creditor to let them know and see if they are willing to write off the debt. (citizens advice)

To write down a debt – to reduce the amount of debt that a person or organisation owes you because it is not possible for them to pay you back the full amount. (Tutor Blog)