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12 articles across 9 topics. Guides for SMS, WhatsApp, voice, SIP and the API.
Browse by topic
Getting startedCreate your account, get a sandbox key and send your first message.1 article →
SMS and DLT (India)Entity, sender ID and template registration for India.2 articles →
Global SMSSender rules, encoding and delivery outside India.1 article →
WhatsApp Business APIOpt-in, templates, the 24-hour window and quality.2 articles →
Voice and SIPIVR flows, SIP trunk setup, caller ID and codecs.1 article →
Campaigns and consentLists, scheduling, opt-outs and sending windows.1 article →
API and webhooksAuthentication, delivery receipts, retries and signatures.2 articles →
Billing and accountBalance, invoices, users and account security.1 article →
TroubleshootingWhy messages fail or arrive late, and how to find out.1 article →
Popular articles
Send your first message in the sandboxGetting started · 6 min readDLT registration checklist for IndiaSMS and DLT (India) · 6 min readHow SMS segments, encoding and cost workGlobal SMS · 6 min readWhatsApp templates and the 24-hour windowWhatsApp Business API · 6 min readWebhooks: delivery receipts, retries and signature checksAPI and webhooks · 5 min readWhy messages fail or arrive lateTroubleshooting · 5 min readOTP messages: delivery and security best practicesSMS and DLT (India) · 6 min read
Latest articles
Getting startedSend your first message in the sandboxCreate a sandbox key, send a test SMS, read the delivery receipt and learn what to change before you go live.13 Oct 2026 · 6 min readSMS and DLT (India)DLT registration checklist for IndiaEntity, header and template registration for commercial SMS in India, in the order that avoids rejections.10 Oct 2026 · 6 min readGlobal SMSHow SMS segments, encoding and cost workWhy a message that looks short can bill as several parts, how encoding decides the limit and how to keep campaigns to one segment.07 Oct 2026 · 6 min readWhatsApp Business APIWhatsApp templates and the 24-hour windowWhen you can send free-form messages, when an approved template is required and how to write templates that are approved and perform.04 Oct 2026 · 6 min readVoice and SIPSIP trunk setup, codecs and caller IDConnect your PBX or dialer to Telnxo, choose codecs, present a valid caller ID and fix the usual one-way audio problems.01 Oct 2026 · 6 min readCampaigns and consentOpt-outs, sending windows and consentPractical rules for collecting consent, honouring opt-outs, choosing sending times and keeping campaigns compliant and healthy.28 Sep 2026 · 5 min read
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