1) Background: Contemporary enterprises are putting more and more emphasis on shaping lasting and effective relationships with clients. This is not an easy task, especially in the conditions of Marketing 4.0, which imposes on enterprises the need to holistically consider the needs as well as the skills and inventiveness of customers. It can be assumed that Clients 4.0 require both changes in the scope of business processes and shaping communication with their environment. That is why it is important today to skillfully and correctly determine the complexity of communication with Clients 4.0, as well as to determine the importance of communication with clients for the development of enterprises-especially those operating in innovative industries. (2) Methods: Empirical research was carried out on a sample of 100 innovative enterprises listed on the NewConnect market in Poland. The respondents were managers at various levels. Two indicators were constructed based on these assessments: Customer Relationships Importance Index (CRII) and Customer Communication Complexity Index (CCCI). (3) Results: It was determined that the complexity of communication of innovative enterprises with customers is at a high level. What is more, the importance of relationships with Customers 4.0 for the development of innovative enterprises is at a high level.It was also indicated that there is no correlation between the level of complexity of relationships with Customers 4.0 and the importance of these relationships for the development of innovative enterprises. (4) Conclusions: Based on the survey, it can be assumed that the relations with Clients 4.0 have the greatest share in shaping the development of innovative enterprises in the areas of minimizing the number of complaints, financial liquidity and efficiency of core business processes. It is also important that, in shaping the complexity of communication with Clients 4.0, enterprises mainly consider traditional phone calls and email account.