We completed an emergency garage repair for a customer. The customer was paid by his insurance and never paid our company for the repair work we rendered.
You ask if you can file a Mechanics Lien for work done but for which you were not paid. The simple answer is 'Yes.' But really, Illinois law already gives you a Mechanics Lien for the value of work-in-place. What you must now do is to "perfect" your Mechanics Lien by giving notice to the Owner and certain other parties. This is most readily accomplished by filing a "Notice of Mechanics Lien" with the Recorder in the County in which this property is located. You must also give notice to all other persons or entities who have an interest in the property - such as a mortgage company, other contractors, etc. This process can be highly technical, so I recommend that you engage a service or Attorney to help you file your Notice of Mechanics Lien and perfect your claim. Finally, remember that you may also sue the owner for breach of contract, unjust enrichment, etc. This can be done in parallell with the Mechanics Lien.
I hope this information was helpful. Best of luck!