Why does my voice AI need a real number? Humans don't see caller-ID flags.

They don't see the FCC VoIP flag, but they DO see the area code, the number format, and (with apps like Truecaller, Hiya, AT&T Call Protect) a 'Spam Likely' label that's auto-applied to most VoIP numbers. Pickup rate on Twilio numbers calling cold: 8-15%. Pickup rate on real carrier numbers: 32-45%. The difference compounds fast at scale.

Can your numbers do outbound calls too?

Yes — the number is the caller ID. You make the actual outbound call through your existing voice provider (Vapi, Retell, Twilio, etc.) configured to spoof the MeiSIM caller-ID via SIP. We provide the number, you provide the dialer.

How does inbound work for a voice AI?

Configure SIP forwarding on the MeiSIM number to point at your voice provider's SIP endpoint. When someone calls the MeiSIM number, the call gets forwarded to Vapi/Retell/OpenAI Realtime which then handles the conversation. Forwarding latency: under 200ms.

Guide · Voice AI

A real US number for your voice AI agent

Your AI agent calls a restaurant for a reservation, or a contractor for a quote, or screens incoming calls on a user's behalf. The other side answers — IF the caller-ID isn't flagged as spam. Twilio numbers get auto-tagged "Spam Likely" by Truecaller, Hiya, AT&T Call Protect. Real carrier numbers don't. Here's how to use ours with the major voice AI platforms.

Real number for your voice AI

Plug into PollyReach, Vapi, Retell, Bland, or OpenAI Realtime via SIP forwarding.

Get the API →

Why pickup rate matters more than you think

Most voice-AI platforms market on conversation quality. That's important. But if 90% of your calls go to voicemail because the recipient sees "Spam Likely," the conversation quality is irrelevant. Pickup rate is the highest-leverage variable.

Concrete numbers from our customers running A/B tests in 2026:

Twilio caller-ID, cold outbound: 8-15% pickup
Real carrier caller-ID (MeiSIM), cold outbound: 32-45% pickup
Real carrier + local area code matching recipient: 50-60% pickup

A 3x improvement in pickup rate is the kind of thing that determines whether a voice AI product has product-market-fit or not.

Integration with the major voice AI platforms

PollyReach

Give your PollyReach agent a real number it'll use for both inbound (answering your line) and outbound (making calls on your behalf). PollyReach lets you import a SIP trunk; point it at the MeiSIM SIP endpoint we provide on number provisioning.

Vapi.ai

In Vapi's number config, choose "SIP trunk" instead of "Twilio." Use the MeiSIM SIP credentials (host, username, password) from your API response. Vapi handles the conversation, MeiSIM provides the carrier identity. Setup time: ~10 minutes.

Retell.ai

Same pattern as Vapi — Retell supports custom SIP trunks. Add MeiSIM as the trunk, set the phone number, route inbound calls to your agent.

Bland.ai

Bland's docs reference "BYO number" via SIP. Plug in the MeiSIM credentials. Outbound calls use the real number as caller-ID.

OpenAI Realtime API

OpenAI Realtime doesn't natively handle telephony — you bridge it via a SIP server (FreeSWITCH, Asterisk, JsSIP). Use the MeiSIM number as the SIP endpoint on the phone side, OpenAI Realtime on the AI side. Most complex integration, also the most flexible.

Provisioning code

POST https://meisimusa-backend.vercel.app/v1/numbers/provision { "plan_id": "p3:1:123", // pick a voice-capable plan "label": "voice-agent-alpha", "sip_forward": { "endpoint": "sip:agent@your-vapi-tenant.com", "format": "rfc3261" } } → { "phone": "+14155551234", "sip": { "username": "meisim_xxx", "password": "xxx", "host": "sip.meisimusa.com:5060" }, "lpa": "LPA:1$smdp.att.com$...", "qr_code": "data:image/png;base64,..." }

Operational notes for voice AI in production

Local area code matching. If your audience is mostly in California, request CA area codes specifically. Recipients in CA see a CA number and pick up more often. (Available on Growth+ tier.)
Number reputation. A number that's been used responsibly for 3-6 months has better deliverability than a fresh one. Reserve numbers for repeat agents instead of spinning up a new number per call.
Two-way SMS. If your voice agent leaves a voicemail, follow up with SMS. The SMS arrives on the same number — looks coherent to the recipient.
Carrier filtering. Even real carrier numbers can be flagged if they exhibit spam-like behavior (high outbound call volume, <5s connect duration). Throttle aggressive outbound to preserve number reputation.

Voice-capable plan + SIP setup

Email us with your voice provider (Vapi / Retell / etc.) — we'll configure the SIP trunk for you.

Email →

FAQ

Why does my voice AI need a real number?

Truecaller, Hiya, AT&T Call Protect auto-flag most VoIP numbers as "Spam Likely." Pickup rates on Twilio: 8-15%. On real carrier: 32-45%. 3x improvement matters.

Can your numbers do outbound calls?

Yes — the number is the caller ID. The actual dialing happens via your voice provider configured with our SIP trunk.

How does inbound work?

SIP forwarding to your voice provider's endpoint. Forwarding latency <200ms.

Which voice AI platforms work with this?

PollyReach, Vapi, Retell, Bland, ElevenLabs Conversational, OpenAI Realtime (via SIP bridge), and any platform that supports custom SIP trunks.