UK & international A2P messaging

SMS for businesses that need it to arrive.

A transactional API, a two-way team inbox, campaigns and automations — on one platform that routes across multiple carriers and tells you the truth about what happened to every message.

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£5 of credit to test with. No card until you send outside the UK.

POST /v1/messages

curl https://api.textmast.com/v1/messages \
  -H "Authorization: Bearer $TEXTMAST_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d to="+447700900123" \
  -d from="ACME" \
  -d body="Your code is 123456"

Built by people who have been burned by the alternatives

Multi-carrier

Routed, not just sent

Every message is scored against live delivery rates per carrier and per country. When a route starts failing, traffic moves before you notice — not after a customer tells you.

3.5p

One price, no bundles

No credit packs, no expiry, no double-credit promotions that make the real cost impossible to work out. One rate per destination, and your live spend on screen.

Honest

Delivery reporting that admits failure

Carrier errors are normalised into reasons that mean something — opted out, number invalid, sender not registered — instead of a numeric code you have to look up.

Four ways to use it

All four run on the same messaging core, so an opt-out recorded in the inbox is respected by a campaign, and a reply to an automated reminder lands in a conversation rather than nowhere.

Transactional API

One REST call to send. Idempotency keys, cursor pagination, signed webhooks with replay protection, and a test mode that costs nothing.

Two-way inbox

A shared team inbox for replies. Assignment, internal notes, canned replies, and a mobile app so an agent can answer from a van.

Campaigns

Lists, segments and scheduled broadcasts, with opt-outs handled for you and a segment counter that tells you the cost before you send.

Automations

Appointment reminders, review requests and follow-ups, triggered on a schedule or a webhook from whatever you already run.

Send your first message in five minutes.

Test keys are issued the moment you sign up, and the sandbox has numbers that fail on purpose so you can build your error handling before you go live.

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