The term "set off" in control account is also called

In bookkeeping and accounting, the term "set off" in control accounts is most commonly referred to as a contra entry.

To explain this in simple terms:

• A contra entry occurs when an amount is recorded in both the debit and credit sides of the same account or two related accounts. Essentially, it's an internal transaction.
• The main purpose of a contra entry is to offset two entries against each other. This is often used to reflect that part of a transaction has cleared or been offset by another transaction.

For example, if a business has an account that records both money received and money spent, a contra entry would allow the business to show that a certain amount received has effectively been set off by a corresponding expenditure.

It’s important because it provides a method to track the exact operations within a business’s accounts, ensuring transparency and accuracy in financial statements.