A previous DUI/DWI conviction in another state may be included as a previous conviction and elevate or enhance the charge for a subsequent DUI/DWI in the driver’s current state of residence—just as if the driver had been convicted of the previous DUI/DWI offense in the driver’s current state of residence.

Whether a previous DUI/DWI conviction in another state is included or stacked on a DUI/DWI charge in the driver’s current state of residence will depend on whether the prosecutor on the current charge becomes aware of the previous conviction. The prosecutor will often become aware of a previous conviction by searching the National Driver Register database—which may include information regarding a driver’s license suspension or revocation provided by the other state in which the driver previously lived and was convicted of DUI/DWI. And if a driver receives a DUI/DWI while visiting another state, the police will notify the Department of Motor Vehicles (DMV) in both the state where the driver was charged with DUI/DWI and the state of the driver’s residence that issued the driver’s current license.

These laws vary from state to state and their application often includes some prosecutorial discretion on whether to include or stack a previous conviction for a DUI/DWI charge in another state on a current DUI/DWI charge in the driver’s state of residence. Some states include, calculate, or stack such a previous DUI/DWI conviction only when the law violated in the other state is sufficiently similar to the DUI/DWI law in the state where the current charge is pending.

In New Jersey, a previous DUI/DWI conviction from another state can be considered when determining the severity of charges and penalties for a subsequent DUI/DWI offense. This is in line with New Jersey's policy of treating out-of-state DUI/DWI convictions as if they occurred within the state, provided that the offense in the other state is substantially similar to New Jersey's DUI/DWI laws. When a person is charged with a DUI/DWI in New Jersey, prosecutors may access the National Driver Register to check for any prior offenses, including those from other states. If a prior out-of-state DUI/DWI conviction is discovered, it can lead to enhanced charges and penalties, similar to having a previous in-state conviction. The decision to include a previous out-of-state conviction is subject to prosecutorial discretion and the specific circumstances of the case.