# Australian Mobile Number Research for AI Assistant (Rivet)

*Compiled by Cog — 2026-02-20*

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## Executive Summary

**Recommendation: Twilio** — best API capabilities for an AI assistant. ~$20-30 AUD/month total for low-volume use.

**Budget option: touchSMS** — Australian-owned, $15/month virtual number + 5c/SMS. Simple, cheap, good API.

**Cheapest possible: Prepaid SIM** — $2-10/month (ALDI PAYG). No API though — manual only.

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## Option 1: Twilio (Recommended for AI)

**What:** Global CPaaS leader. Full programmable SMS + Voice API. Australian mobile numbers available.

| Item | Cost (USD) | Cost (AUD approx) |
|------|-----------|-------------------|
| AU Mobile Number lease | ~$6.00/month | ~$9.50/month |
| Outbound SMS (AU) | $0.055/message | ~$0.09/message |
| Inbound SMS | $0.0075/message | ~$0.01/message |
| Outbound Voice (AU mobile) | ~$0.035/min | ~$0.055/min |
| Inbound Voice | ~$0.0085/min | ~$0.014/min |

**Monthly estimate (low use — 50 SMS, 30 min voice):** ~$20-25 AUD/month

**Pros:**
- Best-in-class API (REST, webhooks, SDKs for every language)
- Full programmable voice (IVR, TTS, recording, conferencing)
- Full programmable SMS (send, receive, two-way conversations)
- Webhook-driven — perfect for Clawdbot integration
- Free trial with credit to test
- 99.95% SLA uptime
- Scales from 1 SMS/day to millions
- WhatsApp Business API available on same number

**Cons:**
- USD pricing (FX fluctuation)
- Prices add up at volume (but we're low-volume)
- US company — data may route through US servers
- Some AU carrier surcharges may apply

**Integration path:** REST API → Clawdbot webhook → Rivet processes messages

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## Option 2: Vonage (Nexmo)

**What:** Major CPaaS competitor to Twilio. Strong AU presence.

| Item | Cost (USD) | Cost (AUD approx) |
|------|-----------|-------------------|
| AU Virtual Number | ~$5.00/month | ~$8.00/month |
| Outbound SMS (AU) | ~$0.05/message | ~$0.08/message |
| Inbound SMS | ~$0.005/message | ~$0.008/message |
| Outbound Voice (AU mobile) | ~$0.07/min | ~$0.11/min |
| Inbound Voice (AU) | ~$0.04/min | ~$0.06/min |

**Monthly estimate (low use):** ~$15-20 AUD/month

**Pros:**
- Slightly cheaper SMS than Twilio
- 99.99% uptime SLA (higher than Twilio)
- Direct Tier 1 AU carrier relationships
- Good API documentation
- Free trial with credit

**Cons:**
- Voice is more expensive than Twilio
- Smaller developer community
- Pricing not always transparent on website (some need sales contact)
- Recently acquired by Ericsson — some uncertainty

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## Option 3: Telstra Messaging API

**What:** Telstra's developer API. Real Australian mobile number on Telstra network.

| Item | Cost |
|------|------|
| API Access | Free |
| Virtual AU Mobile Number | 1 free number included |
| Outbound SMS | Per-message (pricing requires enterprise signup) |
| Inbound SMS | Free |
| Voice | Not available via API (SMS only) |

**Pros:**
- **Australian carrier** — messages come from a real Telstra mobile number
- Highest delivery rates to AU numbers (direct network)
- Free virtual number included
- Free inbound SMS
- No international data routing concerns

**Cons:**
- **SMS only — no voice API**
- Enterprise/business signup required (not self-service like Twilio)
- Pricing not transparent — need to contact sales
- Limited developer ecosystem compared to Twilio/Vonage
- API less feature-rich (no webhooks for real-time inbound, polling required)
- Free tier was generous (1000 SMS/month) but current limits unclear

**Verdict:** Great if we only need SMS. But no voice = limited for a full AI assistant.

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## Option 4: touchSMS (Australian Local)

**What:** Australian-owned SMS platform with virtual numbers and API.

| Item | Cost (AUD ex GST) |
|------|-------------------|
| Virtual Number (SMS + MMS) | $15/month |
| Virtual Number (SMS + Call Forward) | $30/month |
| Virtual Number (SMS + VoIP via VoIPline) | $10/month |
| Outbound SMS | $0.05/credit (1 credit = 1 SMS) |
| Inbound SMS | Free |
| MMS | 3 credits ($0.15) |
| Min credit purchase | $20 = 400 credits |

**Monthly estimate (SMS only, 50 messages):** ~$17.50 AUD/month
**Monthly estimate (SMS + call forward, 50 messages):** ~$32.50 AUD/month

**Pros:**
- **Australian company** — data stays in AU
- Cheapest virtual number option
- No contracts, no setup fees
- Credits never expire
- Free inbound SMS
- Simple REST API
- Free trial (10 credits)
- Good for basic two-way SMS

**Cons:**
- No programmable voice (only call forwarding)
- Smaller platform — less robust than Twilio
- No advanced features (IVR, TTS, recording)
- API less sophisticated than Twilio/Vonage

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## Option 5: Prepaid SIM (Budget Baseline)

**What:** Physical SIM card in a device. Cheapest possible real number.

| Provider | Plan | Cost/month | Includes |
|----------|------|-----------|----------|
| ALDI Mobile PAYG | Pay As You Go | ~$2/month (keep alive) | 12c/min calls, 12c/SMS, $2 SIM |
| ALDI Mobile | $23 plan | $23/month | Unlimited calls/SMS, 12GB data |
| Boost Mobile | $10 prepaid | $10/month | Unlimited calls/SMS, 2GB data |
| Belong (Telstra) | $15 SIM only | $15/month | Unlimited calls/SMS, 5GB data |

**Pros:**
- Cheapest real Australian mobile number
- Full SMS + voice capability
- Real carrier number (not virtual)
- Can receive verification codes, WhatsApp, etc.

**Cons:**
- **No API** — can't programmatically send/receive
- Needs physical device running 24/7
- Can't integrate with Clawdbot without middleware (like a phone + Tasker/macOS shortcuts)
- Not scalable, not automatable
- Would need Signal/WhatsApp bridge to be useful

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## Comparison Matrix

| Feature | Twilio | Vonage | Telstra API | touchSMS | Prepaid SIM |
|---------|--------|--------|-------------|----------|-------------|
| AU Mobile Number | ✅ | ✅ | ✅ | ✅ | ✅ |
| SMS API | ✅ Full | ✅ Full | ✅ Basic | ✅ Basic | ❌ |
| Voice API | ✅ Full | ✅ Full | ❌ | ❌ (fwd only) | ❌ |
| Webhooks (real-time) | ✅ | ✅ | ⚠️ Polling | ✅ | ❌ |
| Programmable IVR | ✅ | ✅ | ❌ | ❌ | ❌ |
| TTS/STT | ✅ | ✅ | ❌ | ❌ | ❌ |
| Call Recording | ✅ | ✅ | ❌ | ❌ | ❌ |
| WhatsApp API | ✅ | ✅ | ❌ | ❌ | Via app only |
| AU Data Residency | ❌ (US) | ❌ (EU) | ✅ | ✅ | ✅ |
| Monthly Cost (low use) | ~$25 AUD | ~$18 AUD | Unknown | ~$18 AUD | ~$10 AUD |
| Setup Complexity | Low | Low | Medium | Low | N/A |
| Clawdbot Integration | Easy | Easy | Medium | Medium | Hard |

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## Recommendation

### For Rivet's AI Assistant Number: **Twilio**

**Why:**
1. **Full SMS + Voice API** — Rivet can send/receive SMS AND make/receive calls programmatically
2. **Webhook-driven** — real-time message delivery to Clawdbot, no polling
3. **Best developer experience** — extensive docs, SDKs, community
4. **WhatsApp Business** available on same number if needed later
5. **Pay-as-you-go** — no commitment, cancel anytime
6. **Proven at scale** — won't hit limits as RateRight grows

**Estimated monthly cost:** ~$20-30 AUD/month (number lease + ~50 SMS + minimal voice)

**Falls within marketing budget:** $1K/month budget easily covers this.

### If budget is the priority: **touchSMS**
- $15/month + 5c/SMS. Australian company, data stays local.
- Good enough for SMS-only use case.
- No voice capability limits its use as a full AI assistant number.

### Not recommended:
- **Prepaid SIM** — no API, can't automate
- **Telstra API** — no voice, enterprise signup friction, unclear current pricing
- **Optus/Vodafone** — neither offers a developer-facing programmable API for virtual numbers

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## Next Steps (If Approved)

1. Sign up for Twilio free trial (no credit card needed)
2. Provision an Australian mobile number (+61 4xx xxx xxx)
3. Configure SMS webhook → Clawdbot endpoint
4. Test two-way SMS with the fleet
5. Optionally configure voice (IVR for RateRight support line)

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*Research complete. Route to Rivet for decision.*