The Data Request Charge (DRC) is a charge intended to curb excessive calls to the Betfair Sports API. This article provides details about how exactly requests are counted. More information about the exact charges and rules can be found here.

You can make 20 requests every second without being charged. Betfair counts requests by logging the time and date that a request is received. Then, the number of requests received in any one second are added together. It is important to note that seconds are counted as wall-clock seconds, i.e. the time between one second and the next on a clock, not as a period of time lasting 1000ms. In other words, if you make 30 requests between 12:02:00 and 12:02:01, you will have exceeded the limit by 10 requests.

If you attempting to calculate the acceptable rate, you should count requests from the start of a real clock second, rather than from an arbitrary point lasting 1 second.

Please also keep in mind that the nature of the Internet means that we suggest you limit usage to 15 requests per second as the default. If you or your customers are betting very little or not at all, this can avoid a charge.

Finally, if you want to synchronise your request counting with Betfair's time, please note the following list of Network Time Protocol (NTP) servers Betfair uses:

• Chimera.csx.cam.ac.uk
• Ntp.maths.tcd.ie
• Dire.bris.ac.uk
• Ntp1.pipex.net