The IRS said that it issued more than nine out of 10 refunds to taxpayers in less than 21 days last year, and expects the same results in 2013.

On its Web page titled What to Expect For Refunds in 2013, the service reports that even though it issues most refunds in less than 21 days, “it’s possible your tax return may require additional review and take longer.”

The page also provides a link to the “Where’s My Refund?” page, which has been updated this year to include a tracker that displays progress through the receipt of the return, its approval and when it was sent. In 2013, clients and preparers can start checking on the status of returns within 24 hours after the service receives an e-filed return, or four weeks after the mailing of a paper return.

The service had come under some criticism early last tax season for delays in issuing refunds, many of which were caused by new anti-fraud processes (see “IRS Fraud Detection System Leads to Refund Delays”), but had largely sorted those issues out by the end of last tax season.