What is an SMS short code? A Clear Guide

A short code is a 5-6 digit number leased for high-throughput A2P SMS. It offers high deliverability and speed but costs more and requires carrier approval.

Why it matters

Getting an SMS short code right keeps you compliant and lands more mail in the inbox. See the deliverability checklist.

How Rainmail helps

Rainmail sends from your own domain on a dedicated, isolated IP with SPF, DKIM, DMARC, reverse-DNS and managed warm-up handled for you, plus an AI watching list health and deliverability — and it welcomes senders SES, SendGrid and Mailchimp reject, from $8. Run the free checker or see plans.