Late fees and what landlords can actually charge
Read the lease clause and the rent ledger. Confirm when rent was due, whether a grace period exists, the fee amount, and how it was calculated. Keep proof of payment, bank records, and any agreement to accept a late payment.
Late-fee rules can depend on state law, the tenancy, and whether the charge reasonably relates to actual costs. Do not assume an arbitrary penalty is valid, and do not assume a fee disappears because you object to it.
Ask for an itemized written explanation. If the charge is tied to a threatened eviction or has grown beyond the lease terms, get local tenant advice promptly. Preserve every notice.