Be sure that if you are unable to make your monthly installment payment, that you contact the IRS. Explain to them why you are unable to make the payment and request that the installment agreement not be defaulted. They may be able to work with you.
If you do not contact the IRS when you know you are having problems making your installment payments, they may void the agreement and seize your assets.
This is especially true if you are paying any delinquent payroll taxes. The IRS does not take lightly when businesses owe these taxes.
If your installment agreement is cancelled, there may be an additional fee to reinstate it.