The Internal Revenue Service issues most refunds sooner than 21 days after receiving a tax return. The status of a refund may be checked using the Where's My Refund function of the IRS website, according to IRS.gov.
In some cases, the IRS may need more time to send a tax refund. If a return contains errors, needs additional review, is incomplete, or is a part of fraud or identity theft, it can take extra time to release a refund. Additionally, if the return contains Form 8379, the Injured Spouse Allocation form, it can take the IRS a supplemental 14 weeks to process the refund.
Filing a request for taxes withheld on Form 1042-S, which is for a foreign person's U.S. income that is subject to withholding on a nonresident alien income tax return, the IRS may need up to six months to complete the refund request.