Driving Under the Influence

Ignition Interlock

Ignition interlock is a device that is installed on motor vehicles to prohibit individuals under the influence of alcohol from operating the vehicle.  Individuals are required to blow into the device before starting the vehicle. If the device detects alcohol, it will prevent the vehicle from starting. In addition, at periodic times during the operation of the vehicle, the driver will be prompted to blow into the device to ensure they are not under the influence.

Ignition Interlock Specifications – please click to view the full set of Ignition Interlock Specifications

Who Do You Contact for Customer Satisfaction or Problem Resolution?
If you have any other questions, comments or concerns, please contact the Pennsylvania Ignition Interlock Quality Assurance Program at:

PA DUI Association
2413 North Front Street
Harrisburg, PA 17110
(717) 238-4354
(717) 238-6211 fax

Ignition Interlock|PA DUI Association

Applying for an Ignition Interlock System/License:

Thirty days prior to an individual’s restoration eligibility date, PennDOT will mail the individual a Restoration Requirements Letter. This letter includes an application for the Ignition Interlock License and a list of ignition interlock providers. The person should complete the application for the Ignition Interlock License and send it to PennDOT immediately. The fee for an Ignition Interlock License varies. (See chart)  Ignition Interlock Licenses have a red banner that contain the words “Limited License”. The red map of Pennsylvania in the lower right corner identifies the type of License as Ignition Interlock. This license permits a person to only drive a vehicle equipped with an Ignition Interlock device.


DL-16LC Acknowledgement of Suspension/Revocation/Disqualification/Cancellation

DL-80 Non-Commercial Driver’s License (Application for Change/Correction/Replacement)

DL-21SCR Self-Certification of Vehicles to be operated requesting removal of ignition interlock systems from vehicles not operated

DL-21SC Self-Certification of Vehicles to be Operated or Inoperable

DL-143 Non-Commercial Driver’s License Application for Renewal

DL-3731 Application for Ignition Interlock License/Return of Regular Driver License

DL-3805 Ignition Interlock Employment Exemption Affidavit

DL-9108 Ignition Interlock Limited License Petition

Ignition Interlock Eligibility Sheet

Contacting an Ignition Interlock Installation Service Center:

If the individual’s second or subsequent DUI violation occurred on or after September 30, 2003, they must contact an Ignition Interlock Installation Service Center. They must complete a DL-21SC form (Self-Certification of Vehicle(s) Owned/Operated) even if no vehicles are owned. The Ignition Interlock staff will verify this information by checking PennDOT’s vehicle database. Once it has been determined that the person does not own any vehicle(s) or has listed all vehicle(s) owned or leased and the device has been installed on all applicable vehicles, the information will be sent to PennDOT. If all restoration requirements have been met and the application for the Ignition Interlock License was received, PennDOT will restore the individual’s driving privilege and issue the Ignition Interlock License.

PennDOT authorized Installation Service Centers (ISC) who carry the approved devices. All systems are leased from the ISC who determines the cost. The approximate cost to lease an ignition interlock system for a year is $1,200. Please note that this list is subject to change.

The Commonwealth of Pennsylvania does not regulate the prices Ignition Interlock Vendors charge for lease and monitoring fees.  Use the DUI Association vendor search page to find out which vendors have installation facilities near you and compare which vendor works best for your needs.

Ignition Interlock Vendor List|PA DUI Association

Getting an Unrestricted License Back:

Thirty days prior to being eligible to receive an unrestricted license, PennDOT will mail the individual an application to apply for an unrestricted license. From the date the Ignition Interlock License was issued until the individual receives an unrestricted license, they may not own, register, drive, operate or be in actual physical control of the movement of any motor vehicle which is not equipped with an ignition interlock system. For more information visit Penn Dot’s Driver and Vehicle Services Website at: www.dmv.state.pa.us For more information visit Penn Dot’s Driver and Vehicle Services Website at: www.dmv.state.pa.us 

Employment Exemption:

An individual who holds an ignition interlock license and is required to drive an employer-owned vehicle for employment purposes, may have their employer complete a DL-3805 form (Ignition Interlock Employment Exemption Affidavit). The Employment Exemption Affidavit allows the individual to operate an employer-owned vehicle not equipped with an ignition interlock system for employment purposes. The Employment Exemption Affidavit cannot be used to drive a school bus, school vehicle, or a vehicle designed to transport more than 15 passengers; an employer-owned motor vehicle owned by an entity which is wholly or partially owned by the person holding the ignition interlock license or an employer-owned vehicle which is made available to the employee for personal use. The Employment Exception Affidavit must be completed in its entirety and be in the driver’s possession while operating an employer-owned vehicle not equipped with ignition interlock. Failure to possess the Affidavit will result in the individual being cited for driving without an ignition interlock.

Hardship Exemption:

An individual who is required to install an ignition interlock system on all of their vehicles may apply to PennDOT for an economic hardship exemption. Pennsylvania’s economic hardship exemption is based on a person’s income level. To qualify for an economic hardship, an individual’s adjusted gross income must be below 200% of the Federal Poverty Guidelines. If an individual qualifies for an economic hardship, they are only required to install an ignition interlock system on one of their motor vehicles. The chart below lists the income levels an individual must meet to qualify for an economic hardship. 

Size of family – Federal Poverty Guidelines – PA Guidelines 200% of Poverty

*for each additional person add $4,320 

If you are applying for a hardship exemption, you must take a copy of your most recently filed federal income tax return to the Installation Service Center.


Individuals convicted of driving a motor vehicle not equipped with an ignition interlock device or tampering with an ignition interlock device is subject to fines and imprisonment. In addition, the individual’s ignition interlock period is extended for 1 year from the conviction date for the 1st offense. Second and subsequent offenses will result in a 1 year suspension. Upon restoration, the individual will be required to hold an Ignition Interlock license for one year plus the balance of the ignition interlock time that remained prior to the suspension being imposed.

Other Penalties:

After the Ignition Interlock device is installed if a person fails to make their vehicle(s) available for maintenance to the Ignition Interlock Service Center, purchases a vehicle and fails to have the Ignition Interlock device installed or requests an unauthorized removal of ignition interlock prior to the eligibility date, the Ignition Interlock Service Center shall notify PennDOT. Upon notification, PennDOT will cancel the individual’s driving privilege until such time the individual is in compliance with the Ignition Interlock requirements.

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