If I take up to an extra 180 days to pay off my total balance, what SPECIFICALLY are the interest and penalties I will see?

You will pay interest, compounded daily until your balance is paid off.  The current interest rate is 8%.

You will also pay a penalty until the balance is paid off.

Failure to pay amount shown as tax on your return

If you don’t pay the amount shown as tax you owe on your return, we calculate the failure to pay penalty in this way:

• The failure to pay penalty is 0.5% of the unpaid taxes for each month or part of a month the tax remains unpaid. The penalty won’t exceed 25% of your unpaid taxes.
• If both a failure to pay and a failure to file penalty are applied in the same month, the failure to file penalty will be reduced by the amount of the failure to pay penalty applied in that month. For example, instead of a 5% failure to file penalty for the month, we would apply a 4.5% failure to file penalty and a 0.5% failure to pay penalty.
• If you filed your tax return on time as an individual and you have an approved payment plan, the failure to pay penalty is reduced to 0.25% per month (or partial month) during your approved payment plan.
• If you don’t pay your tax in 10 days after getting a notice from us with our intent to levy, the failure to pay penalty is 1% per month or partial month.
• We apply full monthly charges, even if you pay your tax in full before the month ends.