Double-booking usually happens when assignment is verbal. Customer A is promised Siti at 10am in a chat; Customer B is promised Siti at 10am in a different chat.
One named person per job
If two jobs need two people, say so. Do not hide a second maid in a remark that only the owner remembers.
Check the calendar before you confirm
Confirmation should happen after you see the person’s day, not before. Recurring jobs count as occupied time.
Handle last-minute swaps in the same system
When a maid is sick, change the assignment on the job. If the swap only happens in WhatsApp, the calendar lies and the next booking will collide again.
Documents do not replace assignment
Passport or condo copies help building access. They do not tell you who is free. Keep documents with the worker record, and keep the booking assignment separate and visible.