budget surplus
US /ˈbʌdʒɪt ˈsɜːrpləs/
UK /ˈbʌdʒɪt ˈsɜːrpləs/

1.
a situation in which a government's income is greater than its spending over a specific period
:
•
The country achieved a significant budget surplus last year due to strong economic growth.
•
A sustained budget surplus can lead to reduced national debt.