I forgot to include a W2 after filing. What do I do?

[bwilliams1114]

I understand the amendment steps and that I should wait until I receive my refund before amending. Will I penalized a great deal and will I be fined for forgetting to include? Also, will a $1680 difference make a great deal if I have to owe money back or receive more money? If I should owe more money, what would the difference in amount average be? Would they send me a letter of money due or a refund check of the difference in the mail?

[MiriamF]

Your questions answered, one by one:

1. There is no penalty for forgetting to include income if you file your amendment before the due date (this year, April 18, 2017). If you wait until after the due date to file, the IRS will begin charging interest on any unpaid balance due. The interest rate is currently 3% per year.
   
2. The IRS does get upset if they determine that you were trying to commit fraud by seriously underreporting your income. In their eyes, $1680 does not count as serious underreporting.
3. If you owe money and you do not pay by the due date, they start charging 3% interest after that date. If you are due a refund, there are no penalties. They might even pay you interest, but only on amounts held after the due date.
4. There is no way to counsel you on how much money you might owe due to the omitted paycheck. You will have to calculate that with TurboTax. If the IRS discovers that you have underreported your income, and you do not file an amendment before the due date, they will send you a letter explaining the changes they have made with an amount due that must be paid within 60 days. You will have the right to challenge their findings.
5. If you are due a refund, they will send you a check by mail. They do that if even you have made an error in data entry that results in lower tax..