Q: My wife and I file a joint tax return and pay estimated quarterly taxes. We usually make a point of overpaying as a caution against unexpected income and also as a way of saving, as we expect a refund. This year … we received a refund of about $1,000. My understanding of the tax rebate is that it is exactly an [advance] against next year’s (2008) taxes. We are due to receive … a total “advance” of $1,200. If, for tax year 2008, we overpay our estimated taxes by, say, $1,000, we would not receive a refund since we would have already received an advance of $1,200. … What is your understanding of this?

— F.T., Westerly

A: The IRS last year received about 115,000 estimated tax payments from Rhode Islanders, so chances are that many other readers are also wondering about the issue you’ve raised.

So what’s the answer? Your federal income-tax liability for 2008 will be calculated in the usual way — regardless of the rebate you receive this year, said Patricia A. Thompson, former president of the Rhode Island Society of Certified Public Accountants.

So if you normally receive a $1,000 federal income-tax refund each year, you’ll receive a $1,000 refund next year, too (assuming that you’ve paid in enough this year), said Thompson, tax partner at Piccerelli Gilstein & Co. LLP, a CPA firm in Providence.

Here’s another way to look at it: If you carefully calibrate your withholding and/or estimated tax payments each year in a way that will generate a $1,000 federal income-tax refund for you each year, that’s what you’ll receive next year, too.

That’s true even if you receive a rebate this year, Thompson said. The rebate is a one-time deal, a kind of bonus. There’s no need to let it interfere with the amount of federal income tax you pay through quarterly estimated payments or withholding.

So if you deliberately pay in more than you know you’ll owe each year in federal income-tax, don’t let the rebate affect your calculations. It’s an extra, a kind of side issue.

Come tax-filing season early next year, you will have to account for the rebate on your tax return. But for most taxpayers, it’ll just be an accounting entry, to let the IRS know that you actually received the rebate. It won’t reduce the amount of your refund next year.

In fact, some taxpayers will wind up with a higher refund. For example, suppose that Mary Taxpayer is eligible for a rebate this year, but doesn’t file her tax return until December — too late for her rebate to be processed. (By law, the Treasury cannot issue rebates after Dec. 31.)

When Mary files her return early next year, covering 2008, she’ll receive that $300 rebate in the form of a one-time credit, right on her 2008 return. It will therefore boost the amount of her refund.

Q: Our Social Security number ended in 17 and we still have not gotten [a] rebate, and it should have been direct deposited.

— J.R., Warwick

A: There are lots of possible reasons.

For example, if you filed your federal income-tax return late in the season, it may not have been processed in time for your rebate to be included in the first round of rebates, Riley said. In that case, you’ll receive your rebate later in the distribution schedule — maybe in June or July.

Here are two new reasons that you may not have received your rebate by direct deposit:

•Payments Astray: About 1,500 rebates that were supposed to be deposited directly into bank or credit union accounts have gone astray, Internal Revenue Service spokeswoman Peggy Riley said yesterday.

“In a few, isolated instances, payments were not made to the proper bank account,” Riley said. It’s not clear why this has happened, and the IRS is working with the taxpayers involved on a case-by-case basis to resolve the problem, she said.

Keep in mind that the number of errant rebates is small compared with the overall number of rebates issued so far.

Since the Treasury began distributions April 28, it has issued about 45.5 million rebates totaling about $40.8 billion.

(In round numbers, that’s about 35 percent of the total number of rebates to be issued this year. So there’s a ways to go yet.)

•Home Software: If you’re eligible for a rebate, but you prepared your own return using tax-preparation software, you may not receive your rebate via direct deposit — even if you filled out the “direct deposit” section on your software program.

Instead, you may receive a rebate check by mail, which takes longer. This could be the case if, for example, you arranged through your software provider to obtain a refund anticipation loan or to have your electronic filing or other such fee deducted from your refund.

TODAY’S TIP: To check on the status of your rebate, use the new online tool available on the IRS Web site:

www.irs.gov

Click on the “Rebate Payment Questions?” link at the top of the page. Then scroll down to the “Where’s My Stimulus Payment?” link.

Or call the IRS toll-free at 1-800-829-1040 (but remember that call volume is high because of the rebates).

Remember, too, that the IRS will mail you a notice letting you know how much of a rebate you’ll receive, when you’ll receive it, and how it was calculated.

Questions about your money matters? Call us at 1-401-277-7484 and leave a message, or e-mail:

moneyline@projo.com

Whether you phone in or e-mail your question, please be sure to include your name, home town and home phone in case we need to reach you. Sorry, no personal replies; as many questions and issues as possible will appear here.