Earned income credit is refundable and available to low and moderate U.S. taxpayers. However, EIC can be disallowed for many reasons. In case it is disallowed for reasons that are not math or clerical errors, then you can file the IRS form 8862 before the IRS gives you the green light to use the service again.
It is worth knowing that you must only file IRS form 8862 once for every credit you are disallowed. If there is attempted fraud in filling out the form, you will be disallowed for ten years.