As competition increases, companies have begun to identify their non-value adding activities in their processes to be more competitive on the market. This has made it possible for companies to compare and prioritize between different problems while various trends of quality costs can be found. Quality costs can be defined as the costs that could be avoided if the company's products or processes were perfect.A complaint starts when a customer's expectations to a product or service is not fulfilled. To create a good customer relationship it is important that the customer feels that the problem is taken seriously and that the company does their best to prevent the same thing happening again. For the company it is important that an accurate and comprehensive declaration is provided on all complaints to get a true overview of the problem.Current management of complaints at Smurfit Kappa Kraftliner can be improved both in management and accounting. An improvement would make it possible to shorten the processing time for warranty claims and the company would get more information from their assemblies.The goal of this thesis is to develop proposals for new procedures and work methods that contribute to the complaint process at Smurfit Kappa Kraftliner to become a more efficient process. In addition, any possible improvements on the current accounting of the complaints will be presented. To fulfill the purpose, the complaint process is mapped and the current accounting method has been identified. Through interviews and observations information has been gathered regarding the handling of complaints. This information has been analyzed based on the theory that deals with effectiveness of processes and quality costs. Furthermore, a literature review has been made in the field of quality and improvement efforts.The analysis showed that to achieve greater efficiency in the process, duplication of tasks and the potential for errors should be eliminated. In addition, standardized activities that make the process faster. A weakness was found in the accounting of complaints during the analysis of the current management that showed lack of possibilities to prioritize the complaints. Smurfit Kappa was recommended primarily to eliminate duplication of tasks in the process and reduce the probability of making mistakes. In addition, to further make the process more effective and to minimize the number of activities, the company can standardize their work. The accounting of claims can be improved by using Pareto charts, and from Pareto analysis quality defect parameters can be used to identify the fundamental problem of the complaint.