The biggest discount of 40 per cent applies to sleeper tickets between Danang and Dieu Tri from October 1 to 31.
Sleeper fares between Danang and Hanoi are being cut by 30 per cent, while several routes, including Hanoi-Danang, Saigon-Nha Trang and Hanoi-Vinh, are offering discounts of 20 per cent.
Other seats and routes are also eligible for discounts of 10-20 per cent during October.
Alongside the October discounts, group promotions are available until December 31 for passengers travelling on HQ1/HQ2 trains on the Tho Loc-Hue-Tho Loc route.
Groups of three pay for two tickets, while groups of six pay for four, using the promotional codes 2tang1 and 4tang2, respectively.
Tickets can be purchased at railway stations or online. For online bookings, passengers should select the 'Adult' category and enter the appropriate promotional code.
All members of a group must travel on the same train, from the same departure station to the same destination. Tickets must be purchased together in a single transaction under the same booking code.
Group tickets cannot be changed or refunded and cannot be combined with other discounts or promotions.
The offer applies only to groups of three or six. For groups of other sizes, tickets outside the eligible group will be subject to standard fare policies.