Even though the IRS issues 9 out of 10 tax refunds within 21 days, it's possible your return may require additional review and take longer to process.

However, if it has been 21 days since your return have been accepted then you may also call the IRS customer service at 1-800-829-1040 to inquire the status of your tax return.

Please see FAQ (click on see entire answer), for more information about, Why some refunds takes longer than others: https://ttlc.intuit.com/replies/3302330