Build your regular budget assuming no child support arrives, then decide how to use each payment when you receive it. Payments have become unreliable, so you can’t safely count on them for recurring expenses. This is consistent with [MoneyHelper’s advice to budget around your lowest dependable income](https://www.moneyhelper.org.uk/en/everyday-money/budgeting/how-to-budget-for-an-irregular-income).

“Borrowing from savings” needs a repayment plan to mean anything. Using savings temporarily to cover essentials can be reasonable, though. The risk is that withdrawals continue indefinitely and hide a monthly shortfall.

Work through the budget together:

- Calculate how much you’re short each month without support. Decide how much you can cover by cutting spending, earning more or making planned withdrawals from savings.
- Put household essentials first: housing, food, utilities, necessary childcare and medical needs. Your wife’s spending and the children’s spending shouldn’t automatically absorb the whole reduction.
- Review everyone’s optional spending. Separate the children’s necessities from optional activities and purchases, and apply the same distinction to adult spending.
- Set limits on using savings. Agree on a maximum monthly withdrawal, a date to stop and a balance you won’t go below. Treat each withdrawal as money spent, without assuming overdue support will replace it.
- Decide how you’ll use support if it arrives. You might cover child-related needs you’ve postponed, then replenish the savings used for household expenses.

If the missing support is $400 a month and you agree to use $1,200 from savings, you have three months to adjust. You’ll still need a budget you can afford after that.

You could say to your wife: “Neither of us caused this missing payment. How do we cover our family’s needs with the money we actually have?” That leaves room for her concern about the children while being clear about what you can afford.

Document missed payments and look into local child-support collection or enforcement options. Keep budgeting based on what you’ve received, even while you pursue what’s owed.