New Manor driver Esteban Ocon will race with the number 31 on his car for the rest of the season after replacing Rio Haryanto.
Haryanto was dropped by Manor after failing to fulfil contractual obligations, with the Indonesian driver's backers owing the team in the region of €7.5million (£6.5m) in funding to complete the season. Mercedes youngster Ocon will drive for the rest of the year, starting with the Belgian Grand Prix on August 28.
Since 2014 drivers have picked their own numbers to use throughout their F1 careers, with the choice having to be made before they enter their first grand prix. Frenchman Ocon has selected the number 31, with Manor confirming his pick via its Instagram account.
Substitute drivers - for one-off races such as Stoffel Vandoorne's appearance at the Bahrain Grand Prix this year - are automatically allocated the reserve number for their respective teams, which they do not have to continue using if they gain a full-time seat. When driving for Renault during Friday practice sessions this season, Ocon has carried the number 45.
While there will be a new number on the front of the Manor at Spa-Francorchamps, there will be a different sponsor on the rear wing after Pertamina decided to end its deal with the team following Haryanto's demotion.