cut back (someone's) spending

Translations
сократить (чьи-то) расходы
To save money, they had to cut back their spending on dining out.
Чтобы сэкономить деньги, им пришлось сократить расходы на ужины вне дома.
Definitions
To reduce the amount of money that someone is spending, often by limiting purchases or being more careful with expenses.