rewindex

CompaniesSinchIncidents

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

MaintenancemaintenanceStatus: scheduledStarted Not resolved3 updatesstspg.io (opens in new tab)

Affected components: Messaging APIs - SMPP - USSMPP - USENUM USLookup API Endpoints - ENUM USHTTP - USMessaging APIs - HTTP - USHTTP USLookup API Endpoints - HTTP US

Timeline of updates

  1. scheduled

    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.

  2. scheduled

    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.

  3. scheduled

    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.

Archive proof

Rewindex commits each version of an incident it captures to a daily checkpoint, chains it to the day before, and has the checkpoint timestamped by FreeTSA and DigiCert. That proves this record existed by then and has not been changed since, by anyone, Rewindex included.

How the archive is checked, and what it cannot prove.

Impact, status and times are the vendor’s own, as last archived. View on stspg.io (opens in new tab).

Cite this

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

Title
Service Announcement & Maintenance: New SMSC Site & Whitelisting Requirements - US Region
Vendor
Sinch
Date
URL
https://rewindex.com/company/sinch/incidents/kfj4nbjzxrqk

Sinch profileRecent Sinch incidentsAll outages on July 10, 2026Sinch in July 2026MarkdownJSON