8.9 Good to know — people

Rate changes never rewrite history. A time entry snapshots the rates in force when the time is recorded, so a raise — or a correction — applies from the next entry forward, and old margins stay as they were reported (§9.11).
Make leavers Inactive; do not delete. Their timesheets, approvals and documents keep pointing at the record, and the headcount simply stops counting them.
Keep supervisors current. The supervisor on the record is an approver of that person's timesheets. A stale supervisor quietly routes approvals to the wrong desk (Chapter 9).
A contact is not a colleague. Contacts (§8.5) are the people at your customers and suppliers; they never sign in, and nothing about them touches payroll, time or permissions.
Bank details are for pay handled elsewhere. Their presence on the record (§8.4) does not make People a payroll (§8.1) — it makes the one conversation with your payroll provider shorter.