You might be on the right track for 3NF but I suggest you take a closer look at your overall design.

You have a client table, but it is mostly populated with IDs for other client-related data. Why not just put all the client data into the client table? Your design demands you now create several bridge tables to tie phone numbers, addresses, etc. to a particular client.

You already have the companies in a separate table, but again, you use IDs to tie information about the company address. You are creating more work for yourself, as again you will have to create and use a bridge table to get meaningful information back about a company.

Why do you have address, email, city, country, phone information in separate tables? Think about what a query would look like if you wanted all the contact information about a particular client or company. You would have to use about 6 tables just to get that.

What you are aiming for is to have all information about a particular thing or event in a table. So you would have all data pertaining to a client in a client table (name, address, phone, email, ID, etc.). Follow this thinking and you will be on your way.