Bengaluru/New Delhi, Sept. 24 -- The festive surge in online sales is being hampered by delivery delays, frustrating customers, potentially denting brand reputation and raising doubts about logistics firms' preparedness to handle high volumes of e-commerce traffic.

Mounting delivery partner attrition and under-staffed warehouses are responsible for the widespread delays-up to 7 days in many cases-in e-commerce and quick commerce deliveries, as well as a backlog of unshipped orders, industry executives and analysts said.

The situation underscores a critical choke point in the industry's supply chain that's unlikely to be resolved quickly, they added.

The hold-up reflects a strain on the entire e-commerce ecosystem's capacity to meet the...