how to connect two phones to one number

Connecting two phones to one number sounds simple, but the “best” solution depends on what you want to share. Some people only need both phones to ring for incoming calls. Others need texting (SMS) to show up on both devices. And some want a complete setup where either phone can call out and still display the same caller ID.

The good news is that you have multiple reliable options. The best one for you will depend on your carrier, your country, and whether you prefer a carrier-based solution or a cloud based number like Google Voice or another VoIP provider.

In this guide, you’ll learn practical methods to connect two phones to one number, how each method works, and the real world limitations you should expect. You’ll also see which approach is best for business use, traveling, and managing multiple devices without missing calls.

Why People Want One Number on Two Phones

A common reason is separating personal life from work while still using a single public number.

Another reason is having a backup phone for emergencies, travel, or battery issues.

Some users switch between an iPhone and an Android and want the same incoming calls wherever they are.

In business, a shared number helps you stay reachable while switching devices or letting a small team answer calls.

Finally, some people want more privacy and use a second phone to avoid carrying their main SIM everywhere.

Step 1: Decide What “One Number” Means for You

Before setting anything up, it helps to be clear about your goal.

Do you want both phones to ring at the same time?

Do you want SMS messages on both phones too, or just calls?

Do you want to place outgoing calls from both phones and keep one caller ID?

These details matter because “call sharing” is typically easier than “text sharing.” Many carriers do not sync SMS across two phones unless they offer a special feature. App based solutions can handle both calls and texts, but they may require a stable internet connection.

Method 1: Carrier Number Sharing (Most Seamless Experience)

Carrier number sharing is the closest thing to a “true” two-phone, one-number setup.

Your carrier links your primary number to another device so calls can ring on both phones.

In some cases, you can also send and receive texts on both devices, but that depends heavily on the carrier’s system.

This solution is often marketed under names like One Number, Number Share, Multi SIM, or a similar label.

How to set it up

Open your carrier app or log into your carrier website.

Look for add-ons or device management options related to multi-device support.

If you can’t find it, contact support and ask specifically for number sharing or multi-SIM.

Your carrier may activate the second phone using an eSIM profile, or provide a plan option that mirrors your number.

After activation, reboot both phones and test incoming calls immediately.

Why it works well

Carrier setups are stable because they don’t rely on third-party apps.

Incoming calls are usually consistent and both phones can ring simultaneously.

If you want a smooth experience with fewer technical steps, this method is usually the best.

What to watch out for

Some carriers charge extra for this feature.

Some carriers do not provide consistent SMS syncing, or they handle it in a limited way.

Voicemail and call history can behave differently depending on how the carrier routes calls.

Method 2: Call Forwarding (Fastest for Calls, No SMS Sharing)

Call forwarding is the easiest method when your main goal is simply not missing calls.

It does not truly “connect” two phones to one number, but it redirects calls from Phone A to Phone B.

This method is perfect if Phone B is a backup phone, or if you only need calls to reach you on a second device during certain hours.

Forwarding modes you can use

Always forward sends every call to Phone B.

Forward when busy sends calls to Phone B if you’re already on a call.

Forward when unanswered sends calls after your phone rings for a set time.

Forward when unreachable forwards calls when Phone A has no signal or is turned off.

How to set it up

On Phone A, open the Phone app settings and find call forwarding.

Choose the forwarding mode you want and enter Phone B’s number.

Save your settings and test by calling your number from a different phone.

What to expect

Phone B will receive the calls, but your SMS messages will still stay on Phone A.

Outgoing calls from Phone B will show Phone B’s number, not Phone A’s number.

Sometimes voicemail will switch to Phone B’s voicemail, depending on the carrier.

Method 3: Google Voice (Calls + Texts Across Two Phones)

If you need calls and texting across two phones, cloud-number services are often the best option.

Google Voice is one of the most popular solutions for this, especially for users who want a single number that works on multiple devices.

With Google Voice, you install the app on Phone A and Phone B and sign in with the same Google account.

You can then receive calls and messages through the app on both phones.

This is also why many people look for ways to buy google voice number online a cloud number can behave like a flexible shared line across devices.

How to set it up

Install Google Voice on both phones.

Sign in with the same Google account.

Choose a Google Voice number if the option is available in your region.

In settings, enable incoming call options and make sure both devices are allowed to ring.

Turn on notifications and disable battery optimization so the app stays responsive.

Why people love it

Both phones can receive calls through the same number.

Texts and call history are available inside the app.

You can also use your number on a desktop browser, which is useful for business.

Limitations

Google Voice availability depends on country and account eligibility.

It relies on internet connectivity for best performance.

Verification and SMS behavior can vary depending on the service and destination.

Method 4: VoIP Provider Apps (Google Voice Alternative)

If Google Voice isn’t available or doesn’t fit your needs, VoIP providers offer similar functionality.

You get a number that lives in the cloud, then log into the provider app on both phones.

Calls and messages are delivered through the app to both devices.

For users who manage online accounts or verification processes, platforms like smsonline are often explored for number flexibility and account separation.

How to set it up

Create an account with your VoIP provider.

Activate a number and make sure the plan includes calling and messaging.

Install the provider app on both phones and sign in using the same account.

Enable notifications and allow background permissions.

Test incoming calls, outgoing calls, and messaging.

Why it’s useful

It works even if you switch devices often.

It’s ideal for business numbers and travel.

It keeps your personal SIM number private and separate.

Method 5: Use Messaging Apps to Reduce the Need for SMS Sharing

If your “texts” are mostly WhatsApp, Telegram, or iMessage, you may not need carrier SMS on both phones.

You can keep your SIM on one phone and keep your messaging account accessible on another device depending on the app’s multi-device support.

This doesn’t fully replicate having SMS on two phones, but it solves communication for most people who rarely use carrier SMS.

Common Issues and Simple Fixes

If only one phone rings in an app based solution, the problem is often battery optimization.

Disable battery restrictions for the VoIP app and make sure notifications are allowed.

If SMS doesn’t appear on both phones, you likely need a cloud-number setup or a carrier feature designed for SMS sharing.

If outgoing calls show different numbers, you need carrier number sharing or an app number like Google Voice to keep caller ID consistent.

Conclusion

To connect two phones to one number, choose the method that matches your goal.

If you want the most seamless, “native” experience and your carrier supports it, Carrier Number Sharing is usually the best option.

If you only care about receiving calls on a second phone quickly, Call Forwarding is the easiest and fastest solution.

If you need calls and texts on both phones, a cloud approach like Google Voice is often the most practical which is why people search for solutions like buy google voice number online.

If Google Voice isn’t available or you want more flexibility, a VoIP provider can do the same job, and some users explore options like smsonline depending on their use case.

The right choice depends on whether you prioritize calls, SMS, or a complete multi device setup.