# Sinch: Service Announcement & Maintenance: New SMSC Site & Whitelisting Requirements - US Region

> Sinch maintenance “Service Announcement & Maintenance: New SMSC Site & Whitelisting Requirements - US Region” on 2026-07-10: impact maintenance (vendor’s label), 3 update(s). Archived by Rewindex.

Canonical: https://rewindex.com/company/sinch/incidents/kfj4nbjzxrqk
Last updated: 2026-10-09T23:30:09Z

- Impact (vendor’s label): maintenance (maintenance)
- Status: scheduled
- Started: 2026-07-10 08:37 UTC · Resolved: not resolved · Duration: ongoing
- Updates: 3 · Affected components: Messaging APIs - SMPP - US, SMPP - US, ENUM US, Lookup API Endpoints - ENUM US, HTTP - US, Messaging APIs - HTTP - US, HTTP US, Lookup API Endpoints - HTTP US
- [Vendor status page: https://stspg.io/pybt2k9s49z9](https://stspg.io/pybt2k9s49z9)
- [Company: Sinch](https://rewindex.com/company/sinch.md)

## Timeline of updates

- **scheduled** 2026-07-10 08:37 UTC: As part of our commitment to platform reliability, security, and scalability, Sinch is adding a brand-new, high-efficiency site to our core SMSC billing and messaging routing engine product. This site expansion introduces a next-generation, high-performance architecture to significantly increase our regional capacity, improve overall platform stability, and ensure robust message processing. New Regional Connection Endpoints that are planned to go live 2026-10-01 during the target window: US SMPP: us6.smpp.api.sinch.com: US HTTP SMS: us6.httpsms.api.sinch.com US Lookup API: us6.httplookup.api.sinch.com Type: Service Announcement & Maintenance Maintenance start time: 2026-10-01 07:00 UTC Maintenance end time: 2026-10-01 08:00 UTC Action Required: Firewall Whitelisting To ensure uninterrupted message delivery as we scale our traffic to include this new site we request that you update your firewall settings. Affected API Endpoint: (This change only affects customers connecting to either of the following US endpoints) US SMPP: us1.smpp.api.sinch.com and/or us7.smpp.api.sinch.com US HTTP SMS: us1.httpsms.api.sinch.com and/or us7.httpsms.api.sinch.com US Lookup API: us1.httplookup.api.sinch.com and/or us7.httplookup.api.sinch.com IP Addresses to Whitelist Please coordinate with your network security team to whitelist these target IP addresses: 35.95.194.74 44.239.11.143 52.32.122.205 If for any reason the maintenance is extended, cancelled, or postponed, we will advise you accordingly. Please contact support@sinch.com should you require further information or assistance.
- **scheduled** 2026-09-24 17:58 UTC: We are writing to inform you that the concerned maintenance activity has been postponed to the below mentioned timeframe. Type: Service Announcement & Maintenance Previous Start Time: 2026-10-01 07:00 UTC Previous End Time: 2026-10-01 08:00 UTC New Start Time: 2026-10-15 07:00 UTC New End Time: 2026-10-15 08:00 UTC As part of our commitment to platform reliability, security, and scalability, Sinch is adding a brand-new, high-efficiency site to our core SMSC billing and messaging routing engine product. This site expansion introduces a next-generation, high-performance architecture to significantly increase our regional capacity, improve overall platform stability, and ensure robust message processing. New Regional Connection Endpoints that are planned to go live 2026-10-15 during the aforementioned time window. US SMPP: us6.smpp.api.sinch.com: US HTTP SMS: us6.httpsms.api.sinch.com US Lookup API: us6.httplookup.api.sinch.com Action Required: Firewall Whitelisting To ensure uninterrupted message delivery as we scale our traffic to include this new site we request that you update your firewall settings. Affected API Endpoint: (This change only affects customers connecting to either of the following US endpoints) US SMPP: us1.smpp.api.sinch.com and/or us7.smpp.api.sinch.com US HTTP SMS: us1.httpsms.api.sinch.com and/or us7.httpsms.api.sinch.com US Lookup API: us1.httplookup.api.sinch.com and/or us7.httplookup.api.sinch.com IP Addresses to Whitelist Please coordinate with your network security team to whitelist these target IP addresses: 35.95.194.74 44.239.11.143 52.32.122.205 If for any reason the maintenance is extended, cancelled, or postponed, we will advise you accordingly. Please contact support@sinch.com should you require further information or assistance.
- **scheduled** 2026-10-09 23:30 UTC: We are writing to inform you that the concerned maintenance activity has been postponed to the below mentioned timeframe. Type: Service Announcement & Maintenance Previous Start Time: 2026-10-15 07:00 UTC Previous End Time: 2026-10-15 08:00 UTC New Start Time: 2026-12-01 07:00 UTC New End Time: 2026-12-01 08:00 UTC As part of our commitment to platform reliability, security, and scalability, Sinch is adding a brand-new, high-efficiency site to our core SMSC billing and messaging routing engine product. This site expansion introduces a next-generation, high-performance architecture to significantly increase our regional capacity, improve overall platform stability, and ensure robust message processing. New Regional Connection Endpoints that are planned to go live 2026-10-15 during the aforementioned time window. US SMPP: us6.smpp.api.sinch.com: US HTTP SMS: us6.httpsms.api.sinch.com US Lookup API: us6.httplookup.api.sinch.com Action Required: Firewall Whitelisting To ensure uninterrupted message delivery as we scale our traffic to include this new site we request that you update your firewall settings. Affected API Endpoint: (This change only affects customers connecting to either of the following US endpoints) US SMPP: us1.smpp.api.sinch.com and/or us7.smpp.api.sinch.com US HTTP SMS: us1.httpsms.api.sinch.com and/or us7.httpsms.api.sinch.com US Lookup API: us1.httplookup.api.sinch.com and/or us7.httplookup.api.sinch.com IP Addresses to Whitelist Please coordinate with your network security team to whitelist these target IP addresses: 35.95.194.74 44.239.11.143 52.32.122.205 If for any reason the maintenance is extended, cancelled, or postponed, we will advise you accordingly. Please contact support@sinch.com should you require further information or assistance.

## Cite this

Maintenance posted by Sinch, started 2026-07-10 08:37 UTC, not resolved, 3 update(s).

- Canonical URL: https://rewindex.com/company/sinch/incidents/kfj4nbjzxrqk
- Citation: Sinch, “Service Announcement & Maintenance: New SMSC Site & Whitelisting Requirements - US Region” (2026-07-10 08:37 UTC). Archived by Rewindex: https://rewindex.com/company/sinch/incidents/kfj4nbjzxrqk (CC BY 4.0).
- Markdown link: `[Sinch: Service Announcement & Maintenance: New SMSC Site & Whitelisting Requirements - US Region (2026-07-10)](https://rewindex.com/company/sinch/incidents/kfj4nbjzxrqk)`


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