Mistakes on tax returns mean they take longer to process, which in turn, may cause your refund to arrive later. The IRS cautions against these common errors so your refund is timely:
1. Incorrect and missing Social Security numbers. When entering SSNs for anyone listed on your tax return, be sure to enter them exactly as they appear on the Social Security cards. The IRS will automatically reject your tax return, tax credits and deductions if your Social Security number is wrong.