Zomato and Swiggy both stated that they do not share customer data with restaurants in order to protect the privacy of consumers. However, this doesn't mean they completely restrict restaurants from contacting customers. Restaurants are provided with a masked number, which they can dial, and the call is automatically redirected to the customer. This allows restaurants to interact with customers without sharing the actual customer number.
The restaurant can find the masked contact number on the order details page on foaps. In case the shared number is unreachable, some restaurants wait for the delivery person to get the contact number, as the delivery person has the customer’s contact number in the rider app.