What does an SLA for SMS actually mean?

A percentage on paper says little without the definitions underneath it. Four questions make clear what you are buying.

What does the percentage cover?

The availability of the platform, or the delivery of messages? Those are two very different promises. Delivery depends partly on operators and on the quality of your numbers.

How is it measured?

Over what period, and what counts as unavailable? Planned maintenance is usually excluded — ask how much of it is allowed.

What happens on a breach?

A credit is common, but it rarely covers your actual loss. So above all know what you have to fall back on when it goes wrong.

What is the response time?

For many organisations this matters more than the uptime percentage. How quickly do you get to speak to somebody, and does that apply outside office hours?

What you do yourself

An SLA is not a fallback plan. Decide what you do if SMS is down for an hour, and test it once.