How to Connect Two Phones to One Number

If you carry more than one device say a personal iPhone and a work Android getting both to ring from the same phone number is incredibly useful. In this guide, you’ll learn the most reliable methods (from zero-cost to pro-grade) to connect two phones to one number, the exact steps, common pitfalls (like OTP/2FA issues), and how to choose the right setup for your needs. We’ll highlight Google Voice, carrier Multi-SIM/Number Share, call forwarding, and cloud PBX options, then wrap up with quick FAQs. If you’re exploring VoIP options or sourcing numbers at scale, you may also see references to buy google voice accounts for business workflows; we’ll explain where that fits and when it makes sense.

The 4 main ways to make two phones share one number

• Google Voice (VoIP fan-out)

Google Voice can ring multiple linked phones when someone calls your Google Voice number. You can also port your current number into Google Voice, then link both devices so they ring together.

• Carrier Multi-SIM / Number Share / Twin-SIM

Many carriers offer a plan that assigns the exact same line to multiple SIMs/eSIMs. Both phones ring and receive SMS on the same number because it’s literally the same subscription cloned across devices.

• Simultaneous ring via cloud PBX

Cloud phone systems (think small business) create a main number that “fan-outs” to several devices at once (ring groups). This is perfect for teams or side businesses.

• Basic call forwarding (limited)

You can forward one line to another, but classic forwarding typically rings only the destination phone, not both simultaneously—unless your carrier supports “simultaneous ring” (a feature more common in business plans).

Method 1: Use Google Voice to ring both phones

This is the most flexible approach for individuals and small teams.

What you need

A Google account and the Google Voice app on both phones.

Either:
a) A new Voice number, or
b) Port your existing number into Google Voice (one-time fee may apply).

Setup steps

1. Create/Access Google Voice. Choose a new number or start the number porting flow.
2. Link your devices. In Settings → Linked numbers, add the mobile numbers of both phones (they can be different carriers or even different countries where supported).
3. Enable call forwarding. Turn on “Receive calls” for each linked number so Voice rings both phones at the same time.
4. Texting setup. Use the Voice app on each phone to send/receive SMS/MMS (some MMS groups or short-codes can be finicky with VoIP; test your key services).
5. Tune your routing. Add schedules, Do Not Disturb, and voicemail greeting.
6. Test. Call the Voice number from a third phone to confirm both devices ring and voicemail works as intended.

Pros

• Works across iOS and Android, and even desktops.
• Rings multiple phones simultaneously.
• Voicemail transcription, call recording (where legal), easy routing rules.

Cons

• Some banks and services don’t accept VoIP for OTP/2FA.
• Emergency calling (911/112) behaves differently than a carrier line.
• If you port in, porting back to a carrier later takes extra steps.

When “buy google voice accounts” appears

For teams that need many ready to use Voice identities (campaigns, support seats), businesses sometimes buy google voice accounts from verified providers to save time. Ensure compliance with Google’s Terms, local regulations, and your KYC needs. If you need consulting or number sourcing, smsonline can help you evaluate compliant options.

Method 2: Carrier Multi-SIM / Number Share (the cleanest for OTP)

With Multi-SIM/Number Share, your carrier issues a second SIM/eSIM for the same number.

Setup steps

• Contact your carrier and ask for “Multi-SIM,” “Twin-SIM,” or “Number Share” for two smartphones (terminology varies by region).
• Provision the second SIM/eSIM on your second phone.
• Confirm both ring & receive SMS. Since it’s one line, OTP/2FA codes from banks typically work on both devices.
• Manage iMessage/FaceTime or RCS as needed (sign-in per device; behavior varies by platform).

Pros

• Most reliable for SMS OTP and short-codes.
• Native calling/SMS with no extra apps.
• Works even when data is off (classic cellular behavior).

Cons

• Availability and pricing depend on your carrier/country.
• Some carriers limit how many devices can share a number.
• International travel costs might double if both phones roam.

Method 3: Cloud PBX with Ring Groups (best for teams)

If you run a small business or a help line, a cloud PBX can ring multiple devices at once, provide IVR (“Press 1 for Sales”), call recording, analytics, and more.

Setup steps

1. Choose a reputable provider.
2. Get a number or port your current number into the PBX.
3. Create a Ring Group with both phones (and any teammates).
4. Set business hours, voicemail, and fallback rules.

Pros

• Enterprise-grade routing and analytics.
• Easy to add/remove devices as your team grows.

Cons

• Monthly subscription; some learning curve.
• OTP to VoIP can be inconsistent (test your critical services).

Method 4: Basic call forwarding (quick but limited)

You can forward Phone A to Phone B or use “simultaneous ring” if your carrier offers it in consumer plans.

Pros

• Fast to set up, often free or low-cost.
• Good as a temporary fallback.

Cons

• Classic forwarding rings only one destination device.
• Missed-call logic can get messy (voicemail picking up on the wrong phone).
• Not ideal for long-term use across two daily-driver phones.

Quick comparison

Choosing what’s right for you

• Need bulletproof OTP and native SMS? Go Multi-SIM/Number Share with your carrier.
• Want flexibility, voicemail transcription, and easy fan-out? Pick Google Voice.
• Running a small team line with reporting? Use a cloud PBX with ring groups.
• Short-term workaround? Basic call forwarding is fine.

Important caveats (read this before you commit)

• 2FA & banking codes: Many banks reject VoIP numbers. If 2FA is critical, prefer Multi-SIM/Number Share.
• Emergency calling: VoIP (including Google Voice) may handle emergency calls differently from carrier lines—know your local rules.
• Messaging apps: WhatsApp, Telegram, and similar support multi-device logins, but they don’t replace cellular SMS/calls.
• Porting: Porting a number into or out of any service can take time and may cause temporary downtime—plan a weekend window.

Mini step-by-step: the fastest “Google Voice + two phones” setup

1. Install Google Voice on both phones and sign in with the same Google account.
2. Pick a new Voice number (or port in your current number).
3. In Settings → Linked numbers, add each phone’s carrier number and toggle Receive calls.
4. Open the Voice app on both phones and allow notifications.
5. Test incoming calls and SMS to confirm both devices ring and messages sync.
6. Add a voicemail greeting and set a quiet schedule if you don’t want both phones ringing at night.

Scaling up? For multi-seat operations you may evaluate providers or buy google voice accounts that are compliant and verified for your region and use case. Always follow Google’s ToS and local telecom laws. Need advice? Visit smsonline .

Bottom line
To truly make two phones act as one number, the most seamless, OTP friendly route is carrier Multi SIM/Number Share. If you prefer flexibility, voicemail transcripts, and easy fan out, Google Voice is excellent especially for freelancers and side businesses. For teams, a cloud PBX gives you ring groups and analytics. Whatever you choose, test your mission critical apps (banking, 2FA, travel logins) before switching full-time.
Need help picking or scaling (including compliant ways to buy google voice accounts for business workflows)? Start a conversation at smsonline.io.