If a taxpayer moves and does not notify the IRS of their new address, the IRS will continue to send notices to the last known address.  If the taxpayer never receives any of the IRS notices, the IRS can proceed with enforcement collection action because the taxpayer did not inform them of their new address and it is the taxpayer’s responsibility to do so.

Depending on where a taxpayer’s case is procedurally, the taxpayer may have other remedies available to them, but it is possible that they could have missed their opportunity to dispute a tax issue, or preserve their appeals rights.  At minimum, taxpayers should make sure they leave a forwarding address with their post office so that they will receive any IRS notices.