Statistics Sweden has been using transaction data in its monthly production of the Consumer Price Index since 2012. Since then, more transaction data of various forms have been introduced, and are continuously being introduced, into the Swedish CPI. As a result, it has become increasingly evident that methodologies need to evolve in order to make the best use of this new type of data. One of the more urgent matters is the need for a unified treatment of the concept of homogeneous products. The impact that a particular price change in transaction data has on an index is often highly dependent on how the distinction between homogeneous and heterogeneous products has been made in practice. The method used for partitioning transaction data into homogeneous products should therefore, in our opinion, be considered one of the most important features when discussing comparability between countries. In this paper we will report on preliminary results from work currently being done at Statistics Sweden in this area.