When a client doubts your expertise, focus on rebuilding trust by understanding their concerns, clarifying expectations, and showcasing your capabilities. Share relevant successes, data, or testimonials, and offer quick wins to demonstrate value early. Transparently explain your process, invite their feedback, and maintain regular updates to ensure alignment. If needed, seek third-party validation to reinforce your approach. Stay professional, avoid defensiveness, and reaffirm your commitment to delivering the best results, turning their doubts into confidence and strengthening the relationship.

The client doesn't know me and even though it would be great if they trust my expertise why should they. In my experience nothing creates trust faster then delivering results. Break the big problem into many small problems and create a roadmap on how you solve the big problem by solving all the little ones. Deliver early on and show that you can be trusted. Don't tell them, show them. And for anyone who still hasn't figures it out, I am a big fan of agile for exactly this reason.

As usual, first and foremost we should let the client know 1. How successfully we executed the similar projects within given timeline 2. Can show the accreditations or certifications that values our core-work 3. Let our KOLs (Key Opinion Leaders) to have direct contact with clients and let them share their experience of working with us. 4. Often, Clients could doubt us due to miscommunication or irrelevant information shared. Ensure that we get the exact requirements from the customers and our solutions are more suitable to them rather than vague one 5. Finally, we can propose small part of project as free trails to show the customers about our expertise in order to gain the credibility.