The default messenger for part of your customer base
Some customer bases reach for a messenger before a phone, and WhatsApp is often the one. Immigration practices see it plainly: demand travels through groups organized by country of origin, on Facebook and on WhatsApp, and the international call lands at hours that are not yours. On the trades side, several electrical companies already show a button to text or write on WhatsApp beside the number: their customers adopted the channel well before their systems did.
Your receptionist answers on that number with the same instructions as on the phone: the same services, the same pricing rules, the same person to alert. She qualifies the request, offers a slot in your calendar when your rules allow it, sends the reminder before the visit, follows up on a quote left hanging if you chose follow-up, and files the thread in your app. A written exchange and a call about one job stay attached to one customer.