An offer in compromise allows you to settle your tax debt for less than the full amount you owe. It may be a legitimate option if you can't pay your full tax liability, or doing so creates a financial hardship.
payment plan is an agreement with the IRS to pay the taxes you owe within an extended timeframe. You should request a payment plan if you believe you will be able to pay your taxes in full within the extended time frame.
By requesting innocent spouse relief, you can be relieved of responsibility for paying tax, interest, and penalties if your spouse (or former spouse) improperly reported items or omitted items on your tax return.
