If I have a DUI and paid it off but did not complete the classes do I have to do jail time?

If you fail to complete all terms of probation, classes, etc, within the specified time you were ordered to do them in, then you will have an arrest warrant issued if you didn't seek an extension of time. What happens after that is up to the judge. While this isn't a 'capital case', yes, you now face potential jail and fines, so handle it right. To handle a warrant, you must turn yourself in to the issuing court, with or without an attorney. On misdemeanors like DUI, an attorney can appear in court without the defendant being present which is safer for you and avoids immediately being taken into custody. You'll try to negotiate a recall of the warrant[s] and bail reduction or OR release. You'll try to negotiate a plea bargain on any Failure to Appear charge or probation violation that caused the warrant. Turning yourself in voluntarily will result in a better outcome than being brought in chains to court after arrest on the warrant. That can happen if you come in contact with law enforcement or customs anywhere in the country. Effective plea-bargaining, using whatever legal defenses, facts and sympathies there may be, could possibly keep you out of jail/prison, or at least dramatically reduce it, and may enable you to get your probation and programs reinstated. Unless you're competent to effectively represent yourself in court against a professional prosecutor trying to put you in jail, most people hire an attorney who can.

The court ordered you to finish the classes. If you didn't that's a probation violation. Yes, many counties will require you do to jail time if you violated probation. My recommendation: Get back into the class and finish it.

Probably not , but it is up to the judge if you have to go back to court. Many counties don't bother with a warrant, the just leave it up to the DMV. You cannot get a license until you complete the program.