What is an SMS sender ID in Australia?
TL;DR: An SMS sender ID is a short brand name that appears as the “from” label on a text instead of a phone number. In Australia it must sit on the ACMA SMS Sender ID Register, and recipients cannot reply to messages sent with one.
What you need to know first
- It shows a name, not a number. Recipients see something like your business name (for example
YourShop) in the sender field. - It is one-way only. People who receive SMS from a sender ID cannot reply. If you need two-way chat, use a dedicated number instead.
- ACMA registration is required. Australia’s SMS Sender ID Register is run by ACMA. You choose a valid name, then lodge through your SMS provider.
- Format rules are strict. Length is 2–11 characters, standard ASCII only, at least one non-digit character, no spaces or underscores, and case is treated the same.
- In SMSFlow you request it from Account settings. Fill a short form (much of it pre-filled). SMSFlow lodges the application for you; ACMA typically approves or rejects within 24 hours.
More detail below if you need it.
How an SMS sender ID looks to recipients
When you send with a mobile or dedicated number, the phone shows that number. With a sender ID, the phone shows your registered name instead.
That helps people recognise your brand at a glance. It suits appointment reminders, order updates, launch notices, and other one-way messages where the brand label matters more than a back-and-forth thread.
It does not create a conversation. There is no reply path back into your Inbox for sender ID traffic. Plan your message copy accordingly (clear next step, link, or support channel if you need a response).
ACMA and why registration matters
The ACMA SMS Sender ID Register exists so brand names on SMS are tied to legitimate businesses and harder to spoof.
For Australian businesses, that means:
- You cannot simply invent a display name and start sending.
- The name must pass format rules and ACMA’s approval process.
- Approval can be rejected; have a backup name ready if needed.
SMSFlow’s Sender ID request flow is built around that process: you submit from Maintenance → Account → General, SMSFlow lodges on your behalf, and ACMA decides. For a plain-English view of the register itself, see our ACMA SMS sender ID register guide.
Format rules in plain English
Before you lodge, check the name against the product-supported rules:
- Between 2 and 11 characters
- Standard ASCII characters (letters, numbers, and supported symbols)
- Must include at least one letter or non-digit character (not numbers-only)
- No spaces anywhere; no leading or trailing spaces or underscores
- Uppercase and lowercase are treated the same
Full checklist: SMS sender ID requirements.
When a sender ID is a good fit
Choose a sender ID when:
- Brand recognition on the lock screen matters more than replies
- You send one-way updates (shipping, reminders, promos with a clear CTA)
- You already handle questions via web form, phone, or email
Choose a dedicated number when:
- Customers need to reply by SMS
- You want inbound messages in Inbox (you still reply via Send SMS, not from Inbox itself)
- You want a number that only your business sends from
SMSFlow includes a free dedicated number with any credit purchase; extra numbers are available monthly. Compare both options in sender ID vs dedicated number. Practical examples live in SMS sender ID use cases.
Compliance and list hygiene still apply
A registered sender ID is not a free pass on consent or spam rules. Keep opt-in clear, identify your business in the message, honour unsubscribes, and keep lists clean. SMSFlow supports unsubscribe keywords, an opt-out message in account settings, and an unsubscribes report. See SMS spam guidelines Australia for a practical checklist (not legal advice).
Common surprises (no replies, ACMA rejection, two-way needs) are covered in SMS sender ID cannot reply.
How sender IDs work in SMSFlow
SMSFlow is a web platform for Australian businesses to send SMS to Australian numbers, manage contacts and groups, run reports, and use an API when you need it.
Relevant points for sender IDs:
- Request a Sender ID under Account settings (General).
- Default sender can be set once you have options available.
- Billing is credit-based; some messages use more than one credit. See pricing.
- New accounts get 50 free credits after signup.
- You must complete verification (including email, ABN, Australian mobile, and 2FA) before you can send.
Campaigns exist in beta for group marketing sends. Contacts are for sending lists, not a full CRM.
FAQ
Can customers reply to an SMS sender ID?
No. Recipients cannot reply when you send with a sender ID. Use a dedicated number if you need replies.
How long does ACMA approval take?
Through SMSFlow’s request flow, ACMA typically approves or rejects within 24 hours after the application is lodged.
Who can request a sender ID on SMSFlow?
SMSFlow is for Australian businesses. You need a valid ABN and the usual account verification steps before sending.
What characters can I use in a sender ID?
2–11 characters, standard ASCII, at least one non-digit, no spaces or underscores. Case is not distinctive.
Is a sender ID the same as a dedicated number?
No. A sender ID is a branded display name for one-way SMS. A dedicated number is a phone number only your business sends from, and customers can reply.
Where do I request a sender ID in SMSFlow?
Account settings (General): use the Sender ID request form. SMSFlow lodges the ACMA application for you.
Start with SMSFlow
If you want branded one-way SMS for an Australian business, request a sender ID after your account is verified, or start with a dedicated number when replies matter. Sign up for 50 free credits, complete verification, then choose the sender that fits the job.