Tax returns are piling up at the Internal Revenue Service, and millions of taxpayers are experiencing refund delays beyond the typical 21 days or fewer for e-filed returns electing a direct deposit refund. The IRS even issued a press release cautioning taxpayers not to count on getting a refund by a certain date, especially when making major purchases or paying bills.

On its operations page update today, the IRS posted that as of March 25, it had 7.2 million unprocessed individual returns, including 4.9 million with errors or needing special handling (paper returns, for example). Both numbers have ticked up since last week by 200,000, suggesting that more returns are going into the “to do” pile as tax day nears.

The good news is that the latest tax filing statistics as of March 25 show that the IRS has processed nearly 79 million individual tax returns and issued nearly 58 million refunds, averaging $3,263. So lots of returns are going through smoothly.

People are always trashing the IRS technology, but the technology is what’s working best,” says Mark Everson, former IRS commissioner and vice chairman of alliantgroup. “If you file a clean return and ask for a direct deposit refund, you’re going to get it quickly. Where they’re struggling is those things that require human intervention.