How much tax benefit did your client get in 2023 from the refunded taxes?

If the sales tax deduction was larger than the income tax withheld, the tax benefit amount would be zero. If the client was over $10k in total Sch A taxes, the tax benefit amount could well have been zero.

It used to be that if you itemized, 99% of the time all of your state refund was taxable. Now it's hardly ever taxable.