question about line 75 - Amount of line 73 you want applied to your 2008 estimated tax

No interest.

But for those who know they will be paying estimated taxes, it is often very convenient to pay some or all of their April 14 estimated tax from their refund.

For those who pay estimated taxes, this is a really good way to make the first installment. In fact I've a couple of clients who say each year "let it (overpayment) ride!". One of these let her last year's overpayment suffice for all four installments for 2008! Talk about convenience!

ChEAr$, Harlan Lunsford, EA n LA (computer fixed)

But you lose lots of interest this way. Better to keep the money in a savings account, CD's, treasurys. With EFTPS, making estimated payments should be pretty easy. Ideally, people making estimated payments should make 5 of them for a tax year -- the usual 4 to pay

That is exactly the way I think and act of course. But remember, everybody in this world is not driven by money. And given the low interest rates in money market funds today, it's not worth the hassle to many people who cultivate peace of mind.

And we all have clients who are just plain forgetful.

ChEAr$, Harlan Lunsford, EA n LA

Most people aren't smart enough to figure that out - or just don't care.