When a person is convicted of or pleads guilty to the offense of Driving Under the Influence (DUI) in Tennessee, the law requires that a judge advise them of the mandatory penalties set by the Tennessee legislature. The judge must also advise the person of enhanced penalties for future DUI convictions.
The judge is not required, however, to advise a defendant of the possible restrictions a Tennessee DUI conviction could place on travel. For instance, once convicted of a TN DUI offense, a person is deemed “criminally inadmissible” to Canada. In fact, if border authorities learn of Tennessee DUI arrest, pending trial, or even the simple issuance of a criminal warrant, you may be denied entry.
Typically, one must follow specific “rehabilitation” procedures to be granted access to Canada following a conviction for driving under the influence. However, a person cannot even begin the application process until a period of five (5) years has passed since the expiration of his or her sentence (rather than 5 years from the date of conviction). In some rare instances, one may be granted a temporary residence permit, which would allow the person entry even during a period of criminal inadmissibility.
Two excellent references on this subject can be found at http://www.tripadvisor.com/Travel-g153339-c49436/Canada:Dwi.Or.Dui.Driving.Convictions.html and http://www.cic.gc.ca/english/visit/faq-inadmissibility.asp#note1.