A spokeswoman for the Internal Revenue Service says there are some common tax mistakes that can delay the processing of your return--and delay your refund if you have one coming.

Karen Connelly with the agency's Denver office says one of the most prevalent problems with tax returns is incorrect or missing Social Security numbers. She says you must enter the Social Security number for anyone listed on your return exactly as that number appears on their Social Security card.  She also says a surprising number of returns are received with a spelling of a name that is different than the spelling on the card. She says even though that may appear to be a minor error, it will cause the agency to return your tax form for correction.

Connelly says math errors and people forgetting to sign their return are also common errors, but she says those only occur on paper returns because the software used for filing electronically  prevents those mistakes.

Connelly says about 80 percent of taxpayers last year filed their return electronically,  with 75 percent of electronic returns filed by people who are due a refund. Connelly says if you file electronically you should get your refund back within about three weeks, assuming there are no errors or problems.