The aim of this study is to learn about and demonstrate the process in which Försäkringskassan (The Swedish Social Insurance Agency) customizes texts and the texts linguistics influence on a potential beneficiary. I use three different questions to fulfill the purpose of the study. I examine what the manuals writers of Försäkringskassan use say about the issues of sentence length, addressing the beneficiaries and wording – three language features that represent different perspectives within plain language research. Furthermore, I examine how decision texts are created and tailored for its beneficiary group and how the language in decisions is perceived by potential beneficiaries. The study’s main method is a case study, which is composed of three data collection methods – comparative text analysis, unstructured interview and survey analysis. The purpose with the different data collection methods is to produce a variety of data that can be discussed in relation to previous research in areas relevant to the purpose of this study. The manuals used by the social insurance staff seem to have a peripheral position on the issue of sentence length, although the survey respondents are expressing criticism towards too long or too short sentences. The study shows that Försäkringskassans decision process is effective, since decisions are created through collaboration of language experts, lawyers and insurance specialists – a collaboration which has also been praised by Språkrådet. However, certain problems arise with the legal language and in some cases Försäkringskassan have to resign themselves to use words and concepts that cannot be described as plain language. The study also demonstrates the need of continuous text reviewing, since the texts should follow current research in plain language and Föräkringskassans guidelines. The fact that Försäkringskassans role as a text transmitter affect the perception of language and content is clear due to results of the survey, a fact which is also supported by previous research. How language is perceived by a beneficiary depends both on the recipient's background knowledge and by his or her attitude towards Försäkringskassan as a text sender.