How to Send SMS From Your App: Node.js, Python and PHP Examples
Copy-ready Node.js, Python and PHP code for sending SMS through the SMS.to API, receiving delivery reports, retrying safely and formatting numbers in E.164.
“Absent Subscriber” and 12 Other SMS Error Codes Explained
“Absent subscriber” means the network knows the number but cannot reach the handset right now. Here is what it and 12 other common SMS delivery errors mean, based on the GSM MAP and SMPP standards, and how to handle each one.
What Is a Text Message API? How It Works, With Code
A text message API lets your software send SMS with a single HTTP request. Here is how it works, with a working curl and Node.js example and a guide to delivery reports.
Free SMS API for Developers: What’s Really Free (and What Isn’t)
Most “free SMS APIs” are free to try, not free to run. This guide explains trial credits, sandboxes, verified-number tiers, SIM-based gateways and email-to-SMS, and the deliverability and legal risks of free routes.
What Does “Invalid Number” Mean in SMS Delivery Reports?
“Invalid number” means an SMS could never reach the destination as addressed. Here are the common causes, how to tell it apart from temporary failures, and how to prevent it with an HLR lookup.
SMS Glossary: 28 Messaging Terms Explained (SMPP, DLR, HLR…)
SMPP stands for Short Message Peer-to-Peer. This glossary defines 28 SMS terms, from delivery reports and sender IDs to HLR lookups, encoding and DLT registration.
Firmao: Streamlining Business with CRM, Tasks, and Invoicing
Firmao is a cloud-based, all-in-one business system covering CRM, invoicing and tasks. Here is what it does and how to connect it to SMS.to through Zapier.
SMS Marketing: A Practical Guide to Getting Started
A step-by-step guide to SMS marketing: getting consent, choosing a sender ID, writing and personalising texts, timing, measuring clicks and handling opt-outs.
SMS Marketing Ideas by Industry: 40 Examples
Forty practical SMS campaign ideas grouped by industry, plus Easter and summer campaigns, each with a short template that fits a single text message.
SMS Marketing Compliance: GDPR, Consent and Opt-Outs
What the law requires before you send marketing texts: valid consent or the soft opt-in, consent records, a free opt-out in every message, quiet hours and sender ID rules.