According to the IRS.gov website, this outlines the topic regarding Interest on refunds which is often asked at IGMR. You can connect here with other people and share your comments and experience regarding interest on refunds if you have not received it within 45 days after the date on your return.
Interest on Refunds
If the refund is made within 45 days after the due date of your return, no interest will be paid. If you file your return after the due date (including extensions), no interest will be paid if the refund is made within 45 days after the date you filed. If the refund is not made within this 45-day period, interest will be paid from the due date of the return or from the date you filed, whichever is later. Accepting a refund check does not change your right to claim an additional refund and interest. File your claim within the period of time that applies. See Amended Returns and Claims for Refund, later. If you do not accept a refund check, no more interest will be paid on the overpayment included in the check.
- You, or a person related to you, caused the erroneous refund in any way, or
- The refund is more than $50,000.
For example, if you claimed a refund of $100 on your return, but the IRS made an error and sent you $1,000, you would not be charged interest for the time you held the $900 difference. You must, however, repay the $900 when the IRS asks.