By default, Enterprise Server for .NET JES regions support job numbers of up to 5 digits (i.e. a maximum job number of 99999). However, if your JES region requires larger job numbers, or is being migrated from a mainframe system configured for 6 digit job numbers, in Enterprise Server for .NET 3.0 and later, you can configure the region to use job numbers of up to 7 digits (i.e. a maximum job number of 9999999).
The format of the spool records for regions configured to use 5 or 7 digit job numbers is different, so if you have a scaled out system which requires the use of regions with 7 digit job numbers, you must ensure that each machine in the scale out has been upgraded to Enterprise Server for .NET 3.0 or later, or those machines will be unable to run jobs in those regions.
All regions that use a shared catalog must be configured to all use either 5 digit job numbers or 7 digit job numbers according to the shared catalog definition (i.e. when a catalog is shared, so are the associated spool records).
You use the region start-up file editor in the Enterprise Server for .NET Administration UI to define the job number range to be used by a JES region.