Illinois law does not require grounds when you file for a legal separation, but there are some restrictions nonetheless. You and your spouse must physically live apart; Illinois does not consider you separated if you’re still under the same roof, even if you’ve terminated your marital relationship. If you’re the spouse filing for separation, you can’t be the one who caused the breakup, and you must attest to this in your petition for separation. Filing for divorce requires grounds. You can file for a no-fault divorce after six-month separation if you’re both in agreement that your marriage is over, and you don't necessarily have to live in separate residences. You can also file on one of nine different fault grounds, including desertion, adultery or addiction.
The procedure for filing in Illinois is the same whether you’re seeking a legal separation or a divorce. You would do it with the circuit court in the county where either you or your spouse live, and you must be a resident of the state for at least six months. The petitions for each action are very similar; in both you’re asking for certain “relief,” or issues you want a judge to decide if you can’t come to an agreement with your spouse on your own.
Illinois’s steps toward a judgment of legal separation and a decree of divorce are the same. If you and your spouse are in agreement about how you want to part ways, your matter is uncontested. You or your attorney can draw up a separation agreement or a marital settlement agreement, detailing the terms. The court will then incorporate your agreement into a court order. If your matter is contested, you’ll move through the usual discovery phase, exchanging documentation to confirm the facts of your case. Negotiations will take place and if you and your spouse can’t reach a consensus, you’ll appear in front of a judge, who will decide the disputed issues for you. With both a separation and a divorce, your final order will address issues of custody, visitation and support. If you chose a legal separation, you can also ask the court to address issues of property division. A legal separation order does not have to divide property, however, unless you want it to, because you’re still married.
A legal separation can last indefinitely, or you can eventually file a request with the court to convert it into a final divorce. Generally, the terms of your separation agreement carry forward into a marital settlement agreement for divorce purposes. If a trial determined issues between you regarding your separation, these terms carry forward as well. Any property you acquire after the date of your legal separation is your separate property and isn’t subject to division between you, if you later convert your separation to a divorce.