# Sender ID registration in Saudi Arabia — the CST process

> All A2P SMS to KSA mobile numbers must use a CST-registered alphanumeric sender ID. CST (Communications, Space and Technology Commission) requires submission through a licensed local aggregator. Registration typically takes 5-10 business days. STC, Mobily, and Zain KSA each maintain their own enforcement databases synced from CST.

- Canonical URL: https://www.broadnet.me/answers/sender-id-registration-ksa-cst
- Language: en
- Last reviewed: 2026-10-01
- Publisher: BroadNet (https://www.broadnet.me)

## Documents CST requires

A Saudi Commercial Registration (CR) number, the corporate Maroof verification, the requested sender ID (max 11 characters, GSM-7 or Arabic — Arabic sender IDs are supported and increasingly preferred), full content samples in Arabic, opt-in proof for marketing senders, and a content-classification statement (transactional vs marketing). Foreign brands without a CR must onboard through a local sponsor or use the brand's regional licensee's CR.

## PDPL 2023 implications

Saudi Arabia's Personal Data Protection Law took full effect in 2024. SDAIA (Saudi Data and AI Authority) is the regulator. Every sender ID registration must now include a PDPL processing-purpose statement, and recipient consent records must be retained for 5 years. Cross-border transfer of recipient MSISDNs requires either adequacy or an explicit SDAIA permit. BroadNet's KSA SMS infrastructure is hosted in-kingdom (Riyadh DC) to keep data resident.

## Arabic sender IDs

Arabic alphanumeric sender IDs are not just permitted but increasingly required for consumer-facing brands. Recipients in KSA tend to respond better to Arabic sender IDs than to transliterated Latin ones. The challenge: not every aggregator's stack handles RTL sender-ID rendering correctly across all operator MSCs. BroadNet ships Arabic sender ID support end-to-end across STC, Mobily, and Zain KSA.

## Common rejection reasons

Brand-name mismatch with the CR. Promotional content under a transactional registration. Sender ID too generic (CST rejects `INFO`, `ALERT`, `OTP` as standalone — it must be brand-tied). Inadequate opt-in documentation. We pre-flight every registration against the latest CST rejection patterns before submission.

## Related

- [All answers](https://www.broadnet.me/answers)
- [Glossary](https://www.broadnet.me/answers)
- [What is an alphanumeric sender ID?](https://www.broadnet.me/answers/what-is-alphanumeric-sender-id)
- [PDPL (KSA) — what the Saudi Personal Data Protection Law means for messaging](https://www.broadnet.me/answers/pdpl-ksa-explained)
- [Sender ID registration in the UAE — the TDRA process](https://www.broadnet.me/answers/sender-id-registration-uae-tdra)
- [What is sender ID spoofing?](https://www.broadnet.me/answers/what-is-sender-id-spoofing)
- [KSA coverage](https://www.broadnet.me/coverage/saudi-arabia)
- [KSA regulations](https://www.broadnet.me/regulations/saudi-arabia)
- [A2P SMS](https://www.broadnet.me/products/a2p-sms)