Nostro and vostro accounts

Nostro and vostro (from Italian, nostro and vostro; English, 'ours' and 'yours') are accounting terms used to distinguish an account held for another entity from an account another entity holds. The entities in question are usually banks.

The terms nostro and vostro are used, mainly by banks, when one bank keeps money at another bank (in a correspondent account often called a nostro or vostro account). Both banks need to keep records of how much money is being kept by one bank on behalf of the other. In order to distinguish between the two sets of records of the same balance and set of transactions, banks refer to the accounts as nostro and vostro. Speaking from the point of view of the bank whose money is being held at another bank:

A nostro is our account of our money (in which country you are staying), held by the other bank or "Foreign Bank".
A vostro is our account of other bank / "Foreign Bank's" money, held by us (by your country's bank)

A vostro account is a record of money held by a bank or owed to a bank by a third party (an individual, company or bank).

The nostro account is a way of keeping track of how much of the bank’s money is being held by the other bank. This is similar to an individual keeping a detailed record of every payment in and out of his or her bank account so that she/he knows the balance at any point in time.