Number Masking

Connect anyone, protect everyone.

Number Masking API that lets your users call and text through temporary proxy numbers — so personal phone numbers stay private. Built on 60,000+ UK numbers with carrier-grade voice quality.

Start Building Free View Documentation

import cloudvno

session = cloudvno.masking.sessions.create(
    participant_1="+447700900001",
    participant_2="+447700900002",
    ttl=3600  # session expires in 1 hour
)

print(session.proxy_number)  # +447000123456
# Either party calls this number → connected to the other

60,000+

UK Numbers

< 200ms

Call Setup

99.99%

Uptime SLA

GDPR

Compliant

Your users need to talk. They shouldn't have to share phone numbers to do it.

Every platform that connects strangers faces the same problem. Delivery drivers need to call customers. Estate agents need to reach property viewers. Marketplace buyers need to message sellers. But the moment personal phone numbers are exchanged, you lose control — off-platform transactions, harassment, spam, and GDPR liability.

Number masking solves this by routing all calls and texts through a temporary proxy number. Both parties communicate naturally, neither sees the other's real number, and when the transaction ends, the connection disappears.

Three API calls. That's it.

Create a session

Your platform tells CloudVNO which two people need to connect. We assign a proxy number from your pool.

Parties communicate through the proxy

Either party calls or texts the proxy number. CloudVNO automatically routes to the other party. Caller ID shows the proxy number, never the real number.

Session ends, connection disappears

When the transaction is complete, your platform closes the session. The proxy number returns to the pool, ready for the next session.

Everything you need to mask at scale.

2-Way Voice Masking

Route calls through proxy numbers with carrier-grade audio quality. Both inbound and outbound calls are masked. Call recording available on request.

2-Way SMS Masking

Text messages forwarded transparently between parties via the proxy number. Supports standard SMS and Unicode messages.

Automatic Session Expiry

Set a TTL on every session. Proxy numbers are automatically released when sessions expire — no cleanup code needed.

Number Pool Management

Bring your own numbers or use our pool of 60,000+ UK mobile numbers. Numbers are automatically allocated and recycled across sessions.

Smart Number Reuse

One proxy number can serve multiple non-overlapping sessions. Our routing engine ensures no collisions.

Real-Time Webhooks

Get notified instantly when calls start, end, are missed, or when SMS messages are sent and received.

Call Detail Records

Complete logs of every masked interaction — duration, direction, timestamps, session ID — accessible via API.

STIR/SHAKEN Attestation

Masked calls carry verified caller ID attestation, reducing spam flags.

Geo-Matching

Automatically assign proxy numbers matching the geographic area of participants. Increases answer rates.

GDPR-Ready

No personal phone numbers exposed. Session data auto-purged after configurable retention. UK/EU data residency.

Built for platforms that connect people.

Delivery & Logistics

Connect delivery drivers with recipients for last-mile coordination. Proxy numbers expire automatically when the delivery is confirmed.

Who uses this: Food delivery apps, courier services, grocery delivery, parcel logistics.

Marketplaces & Classifieds

Let buyers and sellers negotiate safely. Track which listings generate calls. Prevent off-platform transactions.

Who uses this: Used goods marketplaces, auto traders, property portals, freelance platforms.

Ride-Hailing & Mobility

Protect rider and driver privacy on every trip. Automatic session creation when a ride is booked, teardown when the trip ends.

Who uses this: Taxi apps, ride-sharing platforms, chauffeur services, car-sharing.

Property & Real Estate

Estate agents can share a masked number on listings instead of their personal mobile. Track enquiries per listing.

Who uses this: Estate agencies, property management, rental marketplaces.

Healthcare & Telemedicine

Connect patients with practitioners without exposing personal numbers. Maintain privacy in compliance with healthcare regulations.

Who uses this: Telemedicine platforms, appointment booking, home care coordination.

Home Services

Homeowners don't need to give their phone number to every plumber or electrician. Masked numbers keep communication open during the job.

Who uses this: Home service platforms, cleaning services, handyman apps.

Recruitment

Connect recruiters and candidates without revealing personal numbers. Sessions can span weeks with configurable TTL.

Who uses this: Recruitment platforms, staffing agencies, HR tech.

Dating & Social

Give users a safe way to move from in-app chat to phone calls without revealing personal details.

Who uses this: Dating apps, social discovery platforms.

Simple, usage-based pricing. No platform fees.

Component	Price
UK mobile proxy number	$0.50/month per number
Voice — per minute	$0.040/minute
SMS — per masked message	$0.010/message
Session creation	Free
Webhooks	Free
Call recording (optional)	$0.005/minute stored

Volume discounts: 50+ numbers: 20% off number rental. 100,000+ minutes/month: custom pricing.

How we compare

	CloudVNO	Twilio Proxy	Plivo
UK number rental	$0.50/mo	$1.00/mo	$0.80/mo
Voice per minute	$0.040	$0.070+	$0.050
SMS per message	$0.010	$0.020+	$0.015
Platform fee	None	None	None
New customer signup	Open	Closed	Open

Free trial: $10 credit on signup — enough for ~20 test sessions.

Under the hood.

Call setup latency	< 200ms
Concurrent sessions per number	1 (no collisions)
Sequential sessions per number	Unlimited (auto-recycled)
Maximum session TTL	30 days
Supported number types	UK mobile (07x), UK landline (01/02), toll-free (0800)
Voice codec support	G.711 (PCMU/PCMA), Opus
SMS support	Standard GSM, Unicode, concatenated messages
Call recording formats	MP3, WAV
API authentication	API key + secret (HMAC)
API format	REST (JSON)
Webhooks	HTTPS POST, configurable retry policy
SDKs	Python, Node.js, PHP, Go, Ruby, Java
Rate limits	100 sessions/second
SLA	99.99% uptime
Data residency	UK / EU
Compliance	GDPR, STIR/SHAKEN, PECR

Full API reference in our docs. Here's a taste.

POST/v1/masking/sessionsCreate a Session

Request body

{
  "participant_1": "+447700900001",
  "participant_2": "+447700900002",
  "proxy_number": "+447000123456",
  "ttl": 3600,
  "callback_url": "https://yourapp.com/webhooks/masking",
  "metadata": {
    "order_id": "ORD-12345",
    "type": "delivery"
  }
}

Response

{
  "id": "ses_8f3a2b1c4d5e",
  "status": "active",
  "proxy_number": "+447000123456",
  "participant_1": "+447700900001",
  "participant_2": "+447700900002",
  "ttl": 3600,
  "expires_at": "2026-03-11T15:30:00Z",
  "created_at": "2026-03-11T14:30:00Z",
  "metadata": {
    "order_id": "ORD-12345",
    "type": "delivery"
  }
}

GET/v1/masking/sessions?status=active&limit=50List Active Sessions

DELETE/v1/masking/sessions/{session_id}End a Session

View Full API Reference

Live in 30 minutes. Not 30 days.

import cloudvno

client = cloudvno.Client(api_key="your_api_key", api_secret="your_api_secret")

# Create a masked session for a delivery
session = client.masking.sessions.create(
    participant_1="+447700900001",  # driver
    participant_2="+447700900002",  # customer
    ttl=1800,  # 30 minutes
    metadata={"order_id": "ORD-12345"}
)

print(f"Proxy number: {session.proxy_number}")
# → Give this number to the driver's app
# → Driver calls it, customer's phone rings

# When delivery is confirmed, end the session
client.masking.sessions.delete(session.id)

Frequently asked questions

Twilio Proxy is closed. We're open.

If you've been looking for number masking infrastructure that's affordable, developer-friendly, and actually available — you just found it. Start building with $10 free credit.

Start Building Free Talk to Sales

Connect anyone, protect everyone.

Your users need to talk. They shouldn't have to share phone numbers to do it.

Three API calls. That's it.

Create a session

Parties communicate through the proxy

Session ends, connection disappears

Everything you need to mask at scale.

2-Way Voice Masking

2-Way SMS Masking

Automatic Session Expiry

Number Pool Management

Smart Number Reuse

Real-Time Webhooks

Call Detail Records

STIR/SHAKEN Attestation

Geo-Matching

GDPR-Ready

Built for platforms that connect people.

Delivery & Logistics

Marketplaces & Classifieds

Ride-Hailing & Mobility

Property & Real Estate

Healthcare & Telemedicine

Home Services

Recruitment

Dating & Social

Simple, usage-based pricing. No platform fees.

How we compare

Under the hood.

Full API reference in our docs. Here's a taste.

Live in 30 minutes. Not 30 days.

Frequently asked questions

Works great with

Phone Numbers API

Programmable Voice

Programmable SMS

Verify API

Number Intelligence

Twilio Proxy is closed. We're open.

Connect anyone, protect everyone.

Your users need to talk. They shouldn't have to share phone numbers to do it.

Three API calls. That's it.

Create a session

Parties communicate through the proxy

Session ends, connection disappears

Everything you need to mask at scale.

2-Way Voice Masking

2-Way SMS Masking

Automatic Session Expiry

Number Pool Management

Smart Number Reuse

Real-Time Webhooks

Call Detail Records

STIR/SHAKEN Attestation

Geo-Matching

GDPR-Ready

Built for platforms that connect people.

Delivery & Logistics

Marketplaces & Classifieds

Ride-Hailing & Mobility

Property & Real Estate

Healthcare & Telemedicine

Home Services

Recruitment

Dating & Social

Simple, usage-based pricing. No platform fees.

How we compare

Under the hood.

Full API reference in our docs. Here's a taste.

Live in 30 minutes. Not 30 days.

Frequently asked questions

How many sessions can one proxy number handle?

What happens if someone calls the proxy number after the session expires?

Can I use my own numbers instead of your pool?

Does masking work internationally?

Is call recording available?

Can I mask SMS as well as calls?

What about WhatsApp?

How does billing work?

What happens during a network outage?

Is there a free trial?

Works great with

Phone Numbers API

Programmable Voice

Programmable SMS

Verify API

Number Intelligence

Twilio Proxy is closed. We're open.