You need to learn db normalization first and foremost. If you are not familiar with that then whatever you have so far likely won't be of much help. At the risk of boring my fellow helpers I repeat my link to helpful posts and suggest you review those you're not familiar with or at least normalization.
https://www.accessforums.net/showthr...773#post521773
As for your project, most helpers here will guide and assist to some level but probably won't build an application for you seeing as how we're all volunteers with limited time to devote to any one issue. I'm seeing a need for at least four tables here (don't know if that's what you started with):
Properties - details of properties
KeyTypes - master, tennant, contractor, tbd
KeySerial - id of key
LoanXactions - rolling log with out and returned fields as Dates
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.