What is the difference between IPO Book-Runner and Underwriter?

IPO Book-runner is also known as Merchant Banker, Book-Running Lead Managers, Lead managers, Lead/Main Underwriter.

An underwriter is also known as Co-manager, manager, broker, agent.

A book-runner is responsible for assisting the issuer on the entire IPO process

An underwriter comes into picture in case of under subscription.

IPO Book-Runner is mandatory for all IPOs

An underwriter is mandatory only in case of SME IPOs.

Issuer pays fees to a merchant banker

Underwriters charge a fee/underwriting commission for the services.