Indian Railways is changing numbers for all types of trains w.e.f. December 20th, 2010. Under the new numbering system trains would now have a 5-digit number replacing traditional 4-digit train numbers.
To find the new train number from the old one click here.
As of now, trains have varying numbers, including three-digit, four-digit and alpha-numeric ones.
According to the new formula, for Mail and Express trains, including Rajdhani and Shatabdi, digit `1′ will be prefixed before the existing four-digit numbers.
Also, five-digit train numbering has become necessary as the four-digit system has been exhausted, said an official, clarifying that the names of the trains will not be changed.
The five-digit scheme will cover all passenger trains, but not freight trains. Once the software is ready, the new numbers will be reflected in both passenger reservation system and train enquiry system.