Your client is not a household, it is an account and its sites
Residential pest control answers a family that saw a mouse. You serve restaurants, grocery stores, managed buildings, offices and warehouses, under contract. Your client is a manager with several addresses, a service frequency in the contract, reports to deliver and a different person in charge at each site.
In Quebec, a permit is required for businesses that sell or use pesticides. The pest control application category of that permit covers this work, and the authorised activities are carried out by certified employees or under the supervision of a certified employee. The permit is valid for three years.
So your receptionist works by site, not by person. She identifies the account and the site first, then records what was seen, where, since when, who is on site and when someone can get in. The sighting is recorded as an issue, tied to the right site, and reaches you under your urgency rule. She gives no product, no dose and no re-entry time over the phone, issues no certificate, and says nothing about a site to someone who has no right to it.