The pair ensured their place by winning their third-round match at the US Open against Brian Baker and Marcus Daniell 6-3 7-6 (9-7).
Murray, who was world doubles number one earlier this year, won the Australian Open with Soares in January.
This year's event runs from 13-20 November.
Soares and Murray lost in the Wimbledon quarter-finals and went out in the third round at the French Open.
But the pair won the Sydney International before the Australian Open and also reached ATP Tour finals in Monte Carlo and Toronto.
Murray, 30, will be making his second consecutive London appearance.
Last year, he and partner John Peers were eliminated in the group stage.
The tournament sees the top eight ranked pairings split into two groups with the top two from each pool making the semi-finals.
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Britain's Jamie Murray and Brazilian Bruno Soares have secured qualification for the ATP World Tour Finals doubles event at the 02 in London in November.