---
title: "What do the -P, -S, -T and -G suffixes on SMS headers mean?"
description: "Under TRAI's February 2025 amendment to the commercial communication rules, the sender name (header) that customers see ends with a **suffix showing the type of message**. This lets recipients tell at a glance whether a message is a promotion or…"
url: "https://www.smsgatewaycenter.com/blog/kb/what-do-the-p-s-t-and-g-suffixes-on-sms-headers-mean/"
updated: "2026-09-18"
category: Bulk SMS / DLT
---

# What do the -P, -S, -T and -G suffixes on SMS headers mean?

Under TRAI's February 2025 amendment to the commercial communication rules, the sender name (header) that customers see ends with a **suffix showing the type of message**. This lets recipients tell at a glance whether a message is a promotion or an important alert.

| Suffix | Message type | Examples |
| --- | --- | --- |
| **-P** | Promotional | Offers, discounts, marketing campaigns |
| **-S** | Service | Order and delivery updates, balance alerts, warranty and safety information |
| **-T** | Transactional | OTPs and transaction confirmations sent right after a customer's action |
| **-G** | Government | Messages from Central or State Government bodies or their authorised agencies |

For example, a customer might see **SGCSMS-S** on a delivery update and **SGCSMS-P** on an offer from the same business.

## What this means for you

- **The suffix comes from your template's category.** Registering each template under the correct category is what shows customers the right suffix.
- **Use the right category for each message.** A promotion registered as a service message risks complaints and action against your registration, and customers learn to trust "-S" and "-T" messages more.
- **Keep sending with your registered header** as usual. Contact support if you're unsure how the suffix applies to your account.

To choose the right category, see *Which category should I register my DLT template under?*

**Official source:** [TCCCPR (Second Amendment) Regulations, 12 Feb 2025](https://www.trai.gov.in/sites/default/files/2025-02/Regulation_12022025.pdf).

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- [What is DLT digital consent, and do I need to act on it now?](https://www.smsgatewaycenter.com/blog/kb/what-is-dlt-digital-consent-and-do-i-need-to-act-on-it-now/)
- [What is the PE-TM chain, and why do messages fail without it?](https://www.smsgatewaycenter.com/blog/kb/what-is-the-pe-tm-chain-and-why-do-messages-fail-without-it/)

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