Home modifications and writing home modification certificate is part of occupational therapists daily work in municipal home nursing. As the population ages and lives longer in their ordinary home this task will increases for the occupational therapist's in the future. The purpose of this study was to describe occupational therapists experiences of home modifications and certificates writing. The authors used a qualitative approach with semi-structured interviews to collect data. The interviews were conducted in homecare in five municipalities from central and southern Sweden. Data were analyzed using qualitative content analysis, which resulted in a main theme, "Cooperation and communication" and three subcategories "The complexity around the certificate", "Procedure and practice" and "The importance of influencing factors". The results revealed that effective cooperation and communication are critical for the entire home modification process to work. How occupational therapists proceeded in cases, and what information was included, differed in the various municipalities. Furthermore, it was discovered that certain factors influenced occupational therapists, patients, as well as the total home modification process.