This paper summarises the recent UK readership accumulation study conducted by NOP on behalf of NRS Ltd. Given the increase in time-based press planning, there has been an increasing demand for up-to-date information on the rate at which average issue readership accumulates. That demand has now been met in the United Kingdom by NRS Ltd and, prior to that in the United States, by a MRI study conducted in the late 1990s. This paper outlines the methodology employed and the modeling work that was undertaken to generate UK accumulation curves. The rates of accumulation are illustrated for each of the major UK newspaper and magazine genres and the results contrasted with those emerging from the US study. We believe that the findings from the UK and US studies will contribute significantly to the worldwide debate on readership accumulation issues.