How to deal with a difficult client

Company accepts projects from many clients. This makes the vendor-client relationship very complex. If managed properly, this can lead to desired and successful results.
Before you start the project, gather the requirements and create a statement of work detailing the scope. Get all parties to sign it. It is important to obtain as many requirements as possible in advance. Even after the scope has been finalized and signed off, some employers will continue to accept changes. This is because the client is influential and highly prospective.
You can build a healthy relationship
Spend time building relationships. Once an atmosphere of mutual trust and cooperation is established, all aspects of project planning and management–including negotiating and problem solving–are much easier to navigate.
How do you deal with clients who want to add or change scope in the worst possible phase of a project’s life cycle?
First, check that you have the proper procurement documents with all clauses clearly documented. Then ask your client to submit a change request to Change Control Board.
Second, ensure that you have the proper processes in place. This includes following them religiously with no exceptions for powerful clients.
Next, consider whether the process was managed by the right people. Compare the people who signed off the project with the people involved in these new issues. It is possible that the people involved in requirement gathering may be different from those who are asking for change. You should also verify that the requirements are being followed at your end. It is possible that requirements were taken by someone in IT who heard them from a manager, a programmer, or an end-user. The specification is then signed by someone who has no understanding of the requirements.
Finally, check if any requirements were missed. Are they so important that their exclusion puts the project at risk. You are well aware that adding requirements at this stage could put your project at serious risk. These requirements can either be critical to your project’s success or not. Some clients play with words by saying that they are experts and it would not take long. Be careful before you commit to anything. It is safe to say, “Let’s come back to you after an impact analysis on other constraints”.
Be Honest
Since no one is perfect, it is safe to tell the truth about the reasons you can’t meet the client’s expectations. Clients will be more trustful of you if this is done. It may be uncomfortable, but it can help you build a better relationship with your client. You have also prevented your client’s expectations from being set incorrectly by your organization.
It is a good idea to clearly define the scope of work, including what is in and what isn’t, so there are no surprises later. Clients often say “we thought it was already covered in the scope.”
If your client is not able to communicate well or is not able to explain his requirements, Reiterating the same thing over and over is the best way to deal with such clients. If people don’t feel comfortable with your approach, you can say “sorry everyone, but I am repeating it so we all understand.” This will set clear expectations and prevent any scope-related conflicts later.