This post is by Tom Herman of The Wall Street Journal.

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Some people have a good reason for not filing their tax returns yet: They can't.

But procrastinators, beware. That excuse will soon disappear.

In early March, the Internal Revenue Service will begin accepting certain types of returns, such as those claiming adoption expenses, that it hasn't been able to process. The IRS website has a list of the forms that can't be processed until the first week of March. An IRS spokesman says a specific date is "still to be announced.”

Most taxpayers could file as of Jan. 30. But others couldn't because the IRS was working on updating its forms and completing the "programming and testing of its processing systems" in the wake of tax-law changes enacted early this year. That law included many changes that affected returns for last year.

In February, the IRS began accepting two major tax forms covering education credits and depreciation. Form 8863 is used to claim two higher-education credits: the American Opportunity Tax Credit and the Lifetime Learning Credit. Form 4562 is used for depreciation and amortization.

"These forms affected the largest groups of taxpayers who weren't able to file following the Jan. 30 opening of the 2013 tax season," the IRS said.

If you have already filed your tax returns for 2012 and are wondering why you haven't gotten your refund, you may need an extra dose of patience. The IRS said recently that it's "experiencing high traffic" on the "Where's My Refund" feature on the website as more tax returns pour in.

"We continue to see large numbers of people coming in to check on 'Where's My Refund,'" the IRS spokesman says. "The refund tool has been working well, but we continue to urge people to check just once a day due to large volumes." The best times to check on a missing refund are evenings and weekends, the IRS says.

Officials also say the agency's telephone service (1-800-829-1954) "has the same information" that is available on the "Where's My Refund" online feature.

The best strategy: File electronically and choose the "direct deposit" option. According to the IRS, nine of 10 taxpayers "typically receive refunds in less than 21 days when they use e-file with direct deposit."

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