Generally, once your return is e-filed you will receive an acknowledgement email within 48 hours. This email will let you know if your return was accepted or rejected. If your return is rejected, you can simply login to your account, make the corrections, and resubmit your return at no additional charge. Once the IRS has accepted your return, the amount of time that it will take to actually receive a refund may vary.
When filing close to the deadlines (April 15 for standard filers, October 15 for those who have filed extensions), certain other deadlines will apply. If your deadline is April 15 and your return gets rejected, you generally have until April 20 to get the return accepted. Generally, as long as your original e-file was submitted prior to the April 15 deadline and the return is accepted by April 20, your return is still considered timely. If your return is accepted after that date, it is considered late. You can still e-file after April 20. However, at that point the return may be considered late.
If your deadline is October 15 (because you filed an extension), and your original submission is rejected you generally have until October 20 to get your return accepted by the IRS. Generally, as long as your original e-file was submitted prior to the October 15 deadline and the return is accepted by October 20, your return is still considered timely. However, unlike April 15 filers, if you are unable to get your return accepted by October 20, you will not be able to e-file your return. Unfortunately, the IRS completely stops accepting electronically transmitted returns at that time. If you are unable to get your return accepted by the IRS prior to October 20, you will have to mail your return in.