The UK Official Download Chart is compiled by The Official UK Charts Company on behalf of the music industry. The chart week runs from Sunday to Saturday, with the chart being published on a Wednesday afternoon, so asto not to clash with the release of the main UK Singles Chart. For a brief time the Top 10 was aired on BBC Radio 1's Chart Show every Sunday afternoon from 4–7 PM, along with the Top 20 albums and the UK Top 40 singles.
The main chart contains the Top 40 downloads; however, usually only the Top 20 are of main interest. For periods in 2006, a Top 200 was published. The chart only uses sales of single-download tracks on non-subscription online music stores. Some downloading services offer a monthly fee plan where generally an unlimited amount of tracks can be downloaded within a month for a certain price. Tracks downloaded in these instances do not qualify.
The first ever Number one track on the download chart was The Pixies Bam Thwok. The single with the longest stay on the UK Official Download Chart is Crazy by Gnarls Barkley hanging on to the top spot for eleven weeks.