Sales information is supplied by “over the counter” retailers, as well as home delivery/mail order retailers and digital stores to constitute the Official Charts Company's “Defined Universe”. This represents approximately 99% of the total UK singles market, 98% of the total UK albums market and over 90% of the total UK video market.
The retailers on the chart panel include all the major high street chains, supermarkets, internet retailers, digital music retailers and mobile download providers.
Because it is impractical to collect sales data from all independent stores, sales data is weighted up from a representative sample of stores. This produces the DUS (Defined Universe Sales figure) for the independent sector.
As video coverage is less than 95%, the video industry also estimates how the whole market has performed, using multipliers which are agreed in consultation with the BVA (British Video Association). The multipliers are calculated periodically for each format and genre and are applied to the DUS figure to give an approximate total market figure.
The Official Charts Company aims to recruit any store in the UK which sells significant numbers of audio or video product per week (excluding record/video "clubs", whose trading terms don’t comply with current chart rules).
For a retailer to become part of the chart panel there are strict criteria. These cover factors such as a solid trading history, stocking a range of music/products, a minimum daily sales volume and the ability to meet the technical specification for reporting.
For further information on reporting your sales data to the chart panel, please contact the Official Charts Company directly on 020 7620 7450.