Missouri’s DWI Implied Consent Laws: Refusing a Blood, Breath, or Urine Test

Are you required to submit to DWI chemical testing in Missouri? What are the penalties for a refusal?

Updated 6/01/2023

As part of a DWI investigation, the officer will typically request that the suspect take a breath, blood, or urine test to determine blood alcohol concentration (BAC) or the amount of drugs in the suspect's system. This article gives an overview of what Missouri law says about DWI chemical testing and the consequences of refusing a test.

Missouri law specifies that all persons who operate a vehicle within the state are deemed to have impliedly consented to DWI chemical testing if they:

In most cases, a driver who refuses to submit to a chemical test can't be forced to do so. Missouri's implied consent statute permits a driver to decline testing, though refusal comes with certain consequences. In order to discourage test refusals, the state is authorized to impose penalties, including license suspension and restrictions (see below).

Consequences of Refusing Alcohol Testing in Missouri DUI Case

Here are some of the possible repercussions of refusing DWI chemical testing in Missouri.

License Revocation for Test Refusals in Missouri

Drivers who refuse a lawful request by an officer to take a breath, blood, or urine test face a one-year license revocation. And if the driver has any prior alcohol-related enforcement contacts (alcohol-related suspensions and revocations and DWI convictions), a minimum six-month ignition interlock device (IID) requirement will follow the revocation.

To be eligible for limited driving privileges during a refusal revocation, the motorist must provide proof that all vehicles he or she intends to drive are equipped with an IID.

The revocation and IID requirements are separate from any criminal consequences resulting from a DWI conviction and can be imposed even if the DWI charge is ultimately dismissed.

Missouri Allows a Refusal to be Used to Prove a DWI at Trial

Many drivers refuse to believe that a DWI can't be proven without a valid chemical test. However, a driver can be convicted of a DWI based on an excessive BAC or being actually under the influence (impaired) of alcohol or any drug. So, the fact that a driver refused to submit to testing can actually be used against them at trial as evidence of impairment. While refusal doesn't exactly prove intoxication, prosecutors often argue a refusal is indicative that the person was trying to hide intoxication.

Missouri Police May be Able to Get a Warrant for a Forced Test

When a driver refuses testing, police still have the option of obtaining a warrant to draw blood. If a judge issues a warrant, the driver no longer has a right to refuse testing; police are even permitted to do the blood draw by force if necessary.

Talk to an Attorney

If you've been arrested for driving while intoxicated in Missouri, you should talk to a DWI lawyer. DWI law is complicated and constantly changing. A qualified DWI attorney can tell you how the law applies to your case and help you decide on the best way to handle your case.

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