Donlen Corporation Data Breach Investigation

Turke & Strauss LLP, a leading data breach law firm, is investigating Donlen Corporation, now known as Sellerco Corporation, regarding its recent data breach. The Donlen Corporation data breach involved sensitive personal identifiable information belonging to an undisclosed number of individuals.


Donlen Corporation is a fleet leasing and management company. Founded in 1965, Donlen Corporation specializes in offering fleet management services, including vehicle financing, acquisition, registration, and re-marketing. Additionally, Donlen Corporation provides consulting, maintenance, and fleet administrative services for leased vehicles. Headquartered in Bannockburn, Illinois, Donlen Corporation primarily operates in the Midwest and employs over 200 individuals.


On or about March 4, 2021, Donlen Corporation experienced a data breach in which the sensitive personal identifiable information in its systems may have been accessed and acquired. Through its investigation, Donlen Corporation determined that an unknown actor may have accessed this sensitive information between February 24 and March 4, 2021. On August 29, 2022, Donlen Corporation began notifying individuals whose information may have been impacted. The exact type of personal information has not been disclosed by Donlen Corporation. However, according to state reporting guidelines, “personal information” can include the following types of information:

  • Name
  • Social Security number
  • Driver’s license or identification number
  • Financial information
  • Medical information
  • Taxpayer information
  • Personal identification number issued by the United States IRS

If you received a breach notification letter from Donlen Corporation:

We would like to speak with you about your rights and potential legal remedies in response to this data breach. Please fill out the form, below, or contact us at (608) 237-1775 or

If you were impacted by the Donlen Corporation data breach, you may consider taking the following steps to protect your personal information.

  1. Carefully review the breach notice and retain a copy;
  2. Enroll in the free credit monitoring service provided by Donlen Corporation;
  3. Change passwords and security questions for online accounts;
  4. Regularly review account statements for signs of fraud or unauthorized activity;
  5. Monitor credit reports for signs of identity theft; and
  6. Contact a credit bureau(s) to request a temporary fraud alert.

Share This Post: