I already filed for an installment plan through the IRS if i do it through you guys that wont double it up will it?

 You can do the following to indicate that you are paying by check, if you have already set up an installment plan with the IRS to pay your taxes owed. In the File section, select I will mail a check. If you choose to pay with your bank account or credit card, TurboTax will charge the total tax due.