Illinois Change of Address is a process for individuals and businesses to notify the Illinois State government of a change in mailing address. This is important for ensuring that important documents, such as tax returns, are sent to the correct address. There are two types of Illinois Change of Address: individual and business. For individuals, the Illinois Change of Address can be done online through the Illinois Secretary of State website. This form is used to update your address for voter registration, driver's license, and other state records. It can also be done via mail, in which the Illinois Secretary of State must be notified of the change. For businesses, the Illinois Change of Address must be done in writing. This includes a letter from the business to the Secretary of State detailing the new address and a copy of the lease or deed showing the new address. The business must also provide the business registration number and the contact information of the business owner. Upon receipt of this information, the Secretary of State will update the business's address on all state records.