Your lease or rental agreement and Illinois state law are the key places to look for answers to this question. Basically, if you pay rent late, you may be hit with a late fee and possibly face the termination of your tenancy. To avoid problems, know when your rent is due and pay it on time.
Look for a clause called Payment of Rent, or something similar. Basically, you want to find out the following:
You’ll also want to check what your lease says regarding the landlord’s right to terminate your entire tenancy if you pay rent late. Unfortunately, many lease and rental agreements don’t spell this out, but simply include a general clause called something like Grounds for Termination of Tenancy, that states that if you fail to comply with a term of your agreement the landlord may terminate your tenancy under rules and procedures required by law. Read on to find out what these rules and procedures are in Illinois.
If you have not paid the rent on time, under state law in Illinois ( 735 Ill. Comp. Stat. § 5/9-209), your landlord may send you a nonpayment of rent notice the day after rent is due, giving you at least five days to pay rent or move; if you do neither, your landlord can file a lawsuit to evict you.
For details on other Illinois rent-related laws, such as the amount of notice a landlord must give to raise the rent, see the Nolo article on Illinois rent rules. And if you simply can’t pay rent on time, consider other options, such as trying to negotiate a partial rent payment. See the Nolo article What to Do and Not to Do if You Can’t Pay Rent on Time for advice.
Finally, keep in mind that you if you constantly pay rent late, and you have a month-to-month rental agreement, your landlord may decide to simply terminate your tenancy with the required amount of notice (30 days in Illinois), rather than deal with the hassle of regularly sending you late rent notices. And even if your landlord does not terminate your tenancy, don’t expect a great reference from your current landlord when you move on to a new apartment.