Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why would you elect to apply a refund to next year's tax bill?
If you have non-salary income, you might be required to file 1040ES estimated tax for the next year on a quarterly basis. You can instead pay some or all in advance from your previous year's refund. In theory, you lose the interest you might have made by holding that money for a few months. In practice it might be worth it to avoid needing to send forms and checks every quarter. For instance if you had a $1000 estimated tax requirement and the alternative was to get 1% taxable savings account interest for six months, you'd make about $3 from holding it for the year. I would choose to just pay in advance. If you had a very large estimation, or you could pay off a high-rate debt and get a different effective rate of return, the tradeoff may be different.