Six applicants doesn't need a CRM. What migrating messy data actually costs you is unrelated to the tool, it comes from inconsistent fields. If one applicant is recorded as "J. Rivera, called Tues" and the next as "Jane Rivera, 555-0102, voicemail", no software will merge those cleanly later. A notebook with the same six columns every time migrates fine. A CRM filled in sloppily does not.
So the useful thing to do now is fix the columns, not the container. Name, contact, date of first inquiry, date and outcome of each contact, decision and the written reason. If you keep those consistent, moving to software later is an afternoon of typing.
The other reason to keep applicant records tidy has nothing to do with efficiency. Fair housing rules mean you may need to show that you applied the same criteria in the same order to every applicant, and the documentation requirements vary by state and sometimes by city. A dated, consistent record of who applied and why each decision was made is the thing that supports that, and a lawyer in your state should confirm what you're required to retain and for how long.
Where software starts earning its keep is when someone other than you touches the records, or when you're managing renewals and inspections across several units and calendar reminders stop holding it. At one unit you're the whole system.
