The IRS usually has 10 years from the date of assessment to collect unpaid taxes, but that statute of limitations can be extended or suspended in particular situations — such as when taxpayers have declared bankruptcy or request collection due process hearings. There are few exceptions in which the I.R.S. can collect forever (fraud and failing to file returns are two of them). Failing to respond the IRS collection efforts could leave you facing serious consequences like wage garnishment, bank levy, property seizure and even tax liens that could significantly affect your credit rating and financial situation for many years to come.