Yes, you can refuse a breathalyzer in Missouri, but refusing triggers an automatic one-year license revocation and gives prosecutors evidence they can use against you in a DWI case. Under the state’s implied consent law, driving on Missouri roads already counts as agreeing to a chemical test once an officer has reasonable grounds to arrest you for driving while intoxicated. Saying no does not make the DWI charge disappear, and in many situations it leaves you worse off than taking the test would have.1Missouri Revisor of Statutes. Missouri Code 577.020 – Chemical Tests for Alcohol Content of Blood
The One-Year License Revocation
The moment you refuse, a civil process starts that runs separately from any criminal DWI case. The Missouri Department of Revenue will revoke your driving privileges for one year.2Missouri Department of Revenue. Refusal to Submit to an Alcohol and/or Drug Test The arresting officer handles the paperwork on the spot. You receive notice of the revocation and a temporary driving permit good for 15 days.3Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test
This revocation does not depend on a DWI conviction. You could win the criminal case outright and still lose your license for a year because of the refusal alone. It is a civil penalty tied to the refusal itself.
If you have a prior refusal or a prior DWI-related contact on your record, the revocation is still one year, but you lose eligibility for any hardship driving privilege during that period. No legal driving at all.
How Refusal Plays Out in a DWI Prosecution
Refusing is not itself a crime in Missouri. No separate charge gets added. But the refusal becomes evidence prosecutors can present at trial, and the argument writes itself: a sober driver would have taken the test.4Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test
Many drivers assume that without a BAC number, a DWI conviction is unlikely. That is a miscalculation. Prosecutors regularly win DWI cases on the officer’s observations of your driving, your performance on field sobriety tests, witness accounts, and the refusal itself. Refusing can actually make the state’s case cleaner: you have given the prosecutor an extra fact to argue while removing the chance that a borderline or below-limit reading could have helped you.
What Should Happen Before You Decide
You have the right to request 20 minutes to try to reach an attorney before deciding on the test. If 20 minutes pass and you still have not agreed, Missouri treats that as a refusal.3Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test
The officer must also explain the consequences of refusing before you decide, including that the refusal can be used against you. If that warning never happened, it can become an issue later in the administrative hearing or the criminal case.
Refusing a Breath Test Does Not Always End Testing
Saying no to the breathalyzer may just change the type of test. Missouri officers can seek a search warrant for a blood draw, and once a judge signs that warrant, you have no legal right to refuse. Warrants are most common in serious cases, especially crashes involving a fatality or significant injury.5Justia. Birchfield v. North Dakota
Missouri courts have held that implied consent alone does not authorize a warrantless blood draw from an unresponsive subject absent exigent circumstances.1Missouri Revisor of Statutes. Missouri Code 577.020 – Chemical Tests for Alcohol Content of Blood The practical point: in a serious enough situation, you can absorb the refusal penalties and still end up with a BAC reading in the case against you.
Can You Drive at All During the Revocation
Losing your license for a year creates real hardship. Missouri offers a limited path back behind the wheel, but eligibility depends on your record.
If you file a petition challenging the revocation and your driving record shows no alcohol-related enforcement contacts in the previous five years, the Department of Revenue will issue a restricted driving privilege while your petition is pending. The restricted privilege covers work, school, or a formal educational program, and it ends when the court resolves your case.6Missouri Revisor of Statutes. Missouri Code 302.535 – Trial de Novo, Conduct, Venue
Any restricted privilege after a refusal revocation requires an ignition interlock device on every vehicle you drive. You pay for installation, maintenance, calibration, and removal. Letting the interlock or your proof of insurance lapse terminates the privilege immediately.7Missouri Revisor of Statutes. Missouri Code 302.309 – Suspension or Revocation of License
Drivers with a prior DWI or prior refusal are generally ineligible for a hardship privilege during the revocation. That gap between first-time and repeat situations is one of the most consequential lines in the whole system.
Challenging the Revocation
You can contest the revocation by filing a petition for a hearing in the circuit court of the county where the arrest happened.6Missouri Revisor of Statutes. Missouri Code 302.535 – Trial de Novo, Conduct, Venue You have 15 days from the date the Department of Revenue mails its decision notice. Miss the deadline and the revocation is final.
The hearing is narrow. The court looks at only three questions:4Missouri Revisor of Statutes. Missouri Code 577.041 – Refusal to Submit to Chemical Test
- Were you arrested or stopped?
- Did the officer have reasonable grounds to believe you were driving while intoxicated (or, for drivers under 21, that your BAC was 0.02 percent or above)?
- Did you actually refuse the test?
Whether you were in fact intoxicated is not on the list. Successful challenges usually attack the second question by showing the officer lacked reasonable grounds, or they target procedural failures such as the officer never explaining the consequences of refusal. Confusion, medical inability, or a language barrier can sometimes show that what looked like a refusal was not one.
Filing the petition does not pause the revocation on its own, but first-time drivers with clean five-year records can get the restricted privilege described above while the case moves.
Drivers Under 21
The rules are harsher for younger drivers. The adult DWI threshold is a BAC of 0.08 percent; for anyone under 21, it drops to 0.02 percent, low enough that a single drink can cross it.1Missouri Revisor of Statutes. Missouri Code 577.020 – Chemical Tests for Alcohol Content of Blood
An officer does not need to arrest an under-21 driver to invoke implied consent. A lawful traffic stop combined with reasonable grounds to believe the driver’s BAC is at or above 0.02 percent is enough, and the same rule applies at a sobriety checkpoint. Refusing carries the same one-year revocation. Taking the test and registering above 0.02 percent produces its own suspension, so the stakes are high either direction.
Getting Your License Back
Reinstatement after the one-year revocation is not automatic. Missouri requires completion of the Substance Abuse Traffic Offender Program (SATOP) before you are eligible to drive again. SATOP involves an assessment and an education or treatment component scaled to your situation. You also need to file proof of financial responsibility (an SR-22 certificate) and pay the Department of Revenue’s reinstatement fee.
If an ignition interlock was part of a restricted privilege along the way, you will need to show compliance with that requirement too. Enrolling in SATOP well before the revocation period ends is the way to avoid an extra gap between the end of the revocation and the day you can legally drive again.