I have to calculate my late fees and add them manually because the automatic late fees feature doesn’t work for me. On the fourth of the month, I charge $25, then $5 per day after that until reaching 10% of the rent due. The automatic late fees feature accepts only a single amount or a percentage, not both. Being able to use one or both would be best. The percentage should be usable as a percentage or a daily dollar amount, and adjustable for the starting and ending dates and/or the maximum amount. The single charge that follows the grace period motivates tenants to pay within that time. The daily charge incentivizes prompt payment afterward. I think these changes would accommodate most landlords.