Laws and sections by number or title, due dates, pages, and updates.
BSE requires trading members to process Throttle Update Notification messages (Template ID 10028) within their front-end trading applications. The Exchange monitors throttle limit utilization on an intra-day basis. It may reduce these limits during trading hours if utilization exceeds pre-determined thresholds. When the Exchange modifies a limit, it sends a notification message to the affected session. This revised limit applies immediately upon receipt of the notification. Members must ensure their systems dynamically process these updates to regulate order flow. Failure to comply with the revised limits may cause order rejections due to throttle limit breaches.
What you must do
Key dates
Who is affected
Thresholds
If you do not comply
Ask about this notice
[Image omitted. See the official document.]
| Notice No. | 20260917-22 |
|---|---|
| Notice Date | 17 Sep 2026 |
| Category | Trading |
| Segment | Equity |
| Department | Trading Development |
| Subject | Advisory on Handling Throttle Limit Update Notification Message |
| Attachments | No Attachment |
[Image omitted. See the official document.]
This is in partial modification to the Exchange circular no. 20260430-18 dated April 30, 2026 regarding Master Circular for Equity segment. Members may note that the throttle limit assigned to ETI session IDs helps to regulate and control the order flow originating from members' trading application. This throttle limit may vary across different sessions of the same member, depending on the session type and configuration. Once configured, the throttle limit remains unchanged, unless revised by the Exchange.
As stated in the ETI API document, the applicable throttle limit for a session ID is communicated to the members' front-end trading application as part of the logon response message (template ID 10001) and throttle update notification (template ID 10028).
In the Equity Segment, the throttle limits are predefined and vary based on the session type. The current throttle limit values are provided in the table below:
| Session Type | Throttle Limit | Time interval (In millisecond) |
|---|---|---|
| HF LITE | 1000 | 1000 |
| HF FULL | 2000 | 1000 |
| LF LITE | 500 | 1000 |
| LF FULL | 2000 | 1000 |
With the objective of enhancing trading efficiency and monitoring orderly market operations, the Exchange shall continuously monitor the throttle limit utilisation across all trading members on an intra-day basis. In the event of utilisation exceeding pre-determined threshold, these limits would be revised and be proportionately reduced during trading hours.
Whenever the Exchange modifies the throttle limit of a session intraday, a Throttle Update Notification message (Template ID 10028) is disseminated to all affected sessions. This message communicates the revised throttle limit value that becomes applicable to the ETI session with immediate effect from the time of notification. The Throttle Update Notification message is already defined in the ETI API document. The members' front-end trading applications are expected to support and process this message appropriately whenever it is transmitted by the Exchange.
This advisory is being issued to reiterate the importance of handling the Throttle Update Notification message by member applications. Members are advised to ensure that their systems are capable of dynamically processing any intraday throttle limit revisions and regulating the order flow in accordance with the updated limits. Failure to comply with the revised throttle limit values may result in order rejections due to breaches of the applicable throttle limits.
[Image omitted. See the official document.]
For any queries, trading members and vendors are requested to contact the technical support team as follows –
Email ID: bse.tech@bseindia.com
Tel No: 022-2272 8053
For & on behalf of BSE Ltd,
| Nawaid Pathan | Tejash Somaiya |
|---|---|
| Vice President | Vice President |
| I.T. Development | Information Technology |
September 17, 2026
