Bus Service 21X, operated by SBS Transit, was a supplementary express service (or “express feeder” service) operating from St. Michael’s and looping at Novena MRT Station along Thomson Road.
The service was introduced under the Bus Connectivity Enhancement Programme (BCEP), and operated only during weekday peak hours.
↺ Thomson Rd (Loop)
- Service 21X serves Jalan Bahagia & Jalan Tenteram towards both Thomson Rd (Novena MRT) & St. Michael’s. Check the bus destination before boarding.
| Route Overview | ||||||||||||
Route  |
St. Michael’s Bus Terminal ↺ Thomson Road (Loop) | |||||||||||
| Passed Through | Jln Bahagia, Jln Tenteram, Kim Keat Rd, Whampoa Dr | |||||||||||
| Route Length | 7.8 km | |||||||||||
| Travelling Time | 29 mins | |||||||||||
| Operator Information | ||||||||||||
| BCM Route Package | Bishan–Toa Payoh Bus Package | |||||||||||
| Former Operator | SBS Transit Ltd | |||||||||||
| Former Depot | Hougang Bus Depot (HGDEP) | |||||||||||
| Former Fleet | Single-deck buses Occasional double-deck bus deployments |
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| Operating Hours | ||||||||||||
| Departure Times from St. Michael’s |
Weekdays (Except Public Holidays) |
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| 06:30 – 10:00 & 16:15 – 19:45 | ||||||||||||
| Operating Frequency | ||||||||||||
| Loop Service | Morning Peak | Evening Peak | ||||||||||
| Weekdays | 9 – 15 mins | 9 – 13 mins | ||||||||||
| Fare Information |
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| Fare | Charges regular distance fares |
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Bus Service 21X provided a faster connection for commuters travelling between Novena MRT and housing estates in Whampoa & Jalan Tenteram. This limited-stop service, which operated only during weekday morning and evening peak hours, is a quicker alternative to the regular Bus Service 21.
The service plies express between Whampoa estate and Novena MRT in both directions—from Kim Keat Rd to Thomson Rd (via Balestier Rd), and from Thomson Rd to Whampoa Dr (via Moulmein Rd and Balestier Rd). At Novena, Service 21X calls at Thomson Rd (Novena Stn) only, the bus stop near Novena Stn Exit B.
Service 21X serves Jalan Bahagia & Jalan Tenteram in both directions. Commuters should check the bus destination before boarding.
Express Feeder Services
Service 21X is the third bus service with the ‘X’ suffix introduced under the BCEP, launched in 2024. These services with the ‘X’ suffix (which LTA refers to as ‘express feeder’ bus services) are designed to benefit residential estates located farther from major transport nodes and town centres. They take more direct routes with fewer intermediate stops compared to their parent service.
Like its parent Service 21, Service 21X is classified as a trunk service, and thus charges regular distance fares.
With the standardisation of express feeder numbering in November 2025, Service 21X was renumbered to Service 456 from 24 Nov 2025.
MRT Station Served:
- NS20 Novena
Route Variant:
- Bus Service 21: Pasir Ris Bus Interchange ↔ St. Michael’s Bus Terminal
Daily
Departure Timings
Weekdays (except Public Holidays)
- From St. Michael’s Bus Terminal:
Morning Peak: 06:30, 06:41, 06:51, 07:00, 07:10, 07:20, 07:30, 07:41, 07:52, 08:03, 08:14, 08:25, 08:36, 08:43, 08:54, 09:05, 09:17, 09:30, 09:45 & 10:00
Evening Peak: 16:15, 16:28, 16:41, 16:54, 17:07, 17:20, 17:33, 17:45, 17:55, 18:05, 18:16, 18:27, 18:37, 18:46, 18:56, 19:05, 19:15, 19:25, 19:34 & 19:45
Gallery
Poster Gallery
Operator History:
- 28 Apr 2025 – 21 Nov 2025: SBS Transit Ltd
Route History:
- 2025 (28 Apr): Introduced between St. Michael’s Ter and Thomson Rd (Loop) as a supplementary express bus service under the LTA’s Bus Connectivity Enhancement Programme (BCEP).
- 2025 (24 Nov): Renumbered to Service 456.
Past Routing:
| Year | Route | |
| Direction 1 (Loop Service) | ||
| 2025 | St. Michael’s Terminal, Whampoa Rd, Whampoa Dr, Jln Bahagia, Jln Tenteram, Jln Bahagia, Kim Keat Rd, Balestier Rd, Thomson Rd (Loop), Moulmein Rd, Balestier Rd, Whampoa Dr, Jln Bahagia, Jln Tenteram, Jln Bahagia, Kim Keat Rd, Whampoa Rd and St. Michael’s Terminal. | |
Back to Bus Services
Renumbered to 126 and 21 goes into Tampines bus package instead
I observed that ridership for the first few days of 21X has been healthy at times but subdued at other instances.
I noticed people still get on bus 21 Opp NKF although getting off at Novena. Perhaps it is because Google still indicates that it takes 21mins to get to Novena using 21X, when it really should be 8mins tops. Google may need to update the travel time so residents realise bus 21X is much faster.
First few days the demand is quite good. There is also “stolen” demand from the Market to Tenteram but overall the demand to and from Novena is healthy!