A legal separation is very similar to a divorce; the only real difference being that you and your spouse will still be married after the separation is granted. A legal separation can address issues such as child custody, visitation and support and division of assets, property and debts. While you will still be legally married to your spouse, a legal separation will affect tax and inheritance matters and other financial issues. In Illinois, although you do not need to state reason for the separation, you must not be the party responsible for the separation to file the petition.
Gather all identifying information for your spouse and children, as well as a list of debts and assets. You will need dates of birth and Social Security numbers for your spouse and children, date of the marriage and separation and an estimate of what your debts and assets are worth.
Determine which court you will be filing the petition in. Most petitions for separation for residents of Chicago will be filed in the Cook County Courts Domestic Relations Division, however you should call that office directly at 312-603-6300 to make sure that you are in the appropriate jurisdiction before preparing the petition.
Prepare the petition. The petition must include the name of the petitioner (you) and the respondent (your spouse), the name of the court your are filing in and a blank space for the cause number at the top. Title the petition "Petition for Separation." Include in the body of the petition the date you were married, the full names and dates of birth of you, your spouse and your children, the date you were separated, whether you have assets and debts to be divided and what you are asking the judge to grant you. Also include a statement that you are not responsible for the separation. Add a certificate of service clause at the end certifying that you have served the opposing party with the petition.
Sign the petition and make several copies. Hand deliver or mail the petition to the court for filing. If you mail the petition, make sure you include a self-addressed stamped envelope so that the court can return a file-stamped copy to you. You will also need to include the filing fee if you elect to mail the petition.
Send a copy of the petition via certified mail to your spouse or have the civil sheriff serve your spouse with the petition to satisfy the certificate of service requirement.