Introduction: How to Travel the World and Still Mobile Message for 3¢ a Day Using an Old IPhone

[UPDATE July 2016 - Of the 4 ChatSim cards I originally purchased only one is still working. I'd like to warn users against purchasing ChatSim (originally Whatsim from ZeroMobile, but now its own company). I leave these instructions online for those of you that still have ChatSim cards that need to be setup, but please be warned that before you get a year's worth of usage as you were promised that ChatSim will ask for constant refills and recharges in bizarre and confusing language. Supposedly your monthly credits can be cannibalized for banned data that you may or may not have even sent. Also if you have unactivated cards you will get a message telling you they have expired. Really not worth the hassle and what was a brilliant low cost business model has turned into unfair business practices.]

This instructable will walk you through the steps to take an old iPhone, swap out SIM chips and create a global phone that can use cellular service in over 150 countries to send text messages using the following apps: Facebook Messenger, WhatsApp, Kik, Line, Black Berry Messenger (BBM), Line, Hike, QQi and Kakao Talk.

If you've ever encountered a huge cell phone bill from traveling internationally or from a teenager's text messaging then this is a great solution for sending unlimited text and emoji messages for only $12 a year.

So what's the catch? ChatSim issues you an International phone number based in Estonia, but it can't be used for making or receiving phone calls or SMS texts. The only use for the phone number is to register it with your mobile messaging apps. The only SMS texts that will get through are for verification texts from their list of supported messaging apps. All other iOS apps that require data service to function will not work on the cellular network, they can only work when you are connected to a WiFi network.


  1. How old of an iPhone? Basically any iPhone other than the original. You need an iPhone 3GS or newer in order to run the WhatsApp app that requires iOS6. This includes iPhone 3GS, 4/s, 5/s/c, 6/+ and 6S/+. This will not work on iPod Touch. It might work on an iPad if you bought a model with cellular data service (you should see a SIM card slot on the side).
  2. What is WhatsApp? This is an app that is popular worldwide for giving unlimited worldwide messaging on almost any smartphone for 99¢ a year.
  3. What is ChatSim? Italian network operator Zero Mobile sells a SIM card that allows your iPhone to switch from your current phone carrier (AT&T, Verizon, T-Mobile, Sprint, etc) to their virtual network that contracts with phone carriers around the world (T-Mobile in the US) to provide almost unlimited text and emoji icons to be sent from supported apps.
  4. What apps are supported? ChatSim supports cellular text data for the following apps: WhatsApp, Telegram, BBM, Facebook Messenger, WeChat, Kik, Line, Hike, Kakao and QQi.Check their website for additions. Other apps like Apple iMessage, Google Voice, Tango are not supported on their network, but still usable when your iPhone is connected to WiFi.
  5. What Countries are supported? 150 of the world's 196 countries! Afghanistan, Albania, Anguilla, Antigua and Barbuda, Argentine, Armenia, Aruba, Australia, Austria, Azerbaijan, Bangladesh, Barbados, Belgium, Bermuda, Bolivia, Brazil, British Virgin Islands, Brunei, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canada, Cape Verde Island, Cayman Islands, Chad, Chile, China, Colombia, Congo, Congo Dem. Republic, Costa Rica, Croatia, Cuba, Cyprus, Czech.Republic, Democratic Republic of Lao, Denmark, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, Equatorial Guinea, Estonia, Faroe Islands, Fiji, Finland, France, French Guyana, Gabon, Gambia, Georgia, Germany, Ghana, Greece, Greenland, Grenada, Guadalupe, Guatemala, Guinea, Guyana, Haiti, Honduras, Hong Kong, Hungary, Iceland, India, Indonesia, Iran, Ireland, Isle of Man, Israel, Italy, Jamaica, Japan, Kazakhstan, Kenya, Korea (South), Kuwait, Kyrgyzstan, La Desirade, Latvia, Les Saintes, Lesotho, Liechtenstein, Lithuania, Luxembourg, Macau, Malawi, Malaysia, Mali, Malta, Marie- Galante, Martinique, Mexico, Moldova, Mozambique, Myanmar, Namibia, Nauru, Nepal, Netherlands, Netherlands Antilles, New Zealand, Nicaragua, Niger, Nigeria, Norway, Pakistan, Papua New Guinea, Panama, Paraguay, Perù, Philippines, Poland, Portugal, Romania, Russia, Rwanda, Samoa, Saudi Arabia, Senegal, Sierra Leone, Singapore, Slovakia, Slovenia, South Africa, Spain, Sri Lanka, St Barts, St. Kitts, St. Lucia, St. Martin, St. Vincent / Grenada, Suriname, Sweden, Switzerland, Taiwan, Tajikistan, Tanzania, Thailand, Timor-Leste, Tonga, Trinidad &Tobago, Turk & Caicos Isl., Turkey, Uganda, Ukraine, United Arab Emirates, United Kingdom, Uruguay, USA, Uzbekistan, Vanuatu, Venezuela, Vietnam, Zambia

Step 1: Make Sure Your IPhone Is UNLOCKED

Make sure you iPhone is UNLOCKED - this means your phone has permission to be used on other mobile networks. Usually your phone company LOCKS your phone to their SIM chip while you are under contract. Once you've paid off your phone the company will let you unlock your phone. You can read Apple's tech note here.

AT&T - Will unlock if requested at the end of any service commitment or installment plan has been met. Must not be reported lost or stolen to unlock.

Sprint - Will unlock at the end of your lease, account is paid in full and device is not reported as lost or stolen. Sprint should automatically unlock once all three items are met.

T-Mobile - Will allow 2 unlocks per line per year. You must still have an account in good standing. Device must not be reported as lost or stolen to unlock.

Verizon - Doesn't lock iphones. If using a 3G World Device you'll have to contact them to unlock.

If you are unable to convince your mobile provider to unlock your iPhone you can take your phone to almost any mobile phone shop and pay them to do it. You can also use an online provider to send you an unlock code. You will need to provide your IMEI number (Settings >General >About >IMEI) and payment.

If you are buying an iPhone make sure that it hasn't been reported as stolen. Cellular carriers check a phone's IMEI number before allowing it on their network. You can use a service like Swappa to verify a phone's IMEI or ESN number is whitelisted before purchasing.

You'll know if your iPhone is still locked if you swap out SIM chips with another provider and it doesn't work, or if you goto Settings and don't have an option for" Carrier" or "Cellular."

Step 2: Order Your ChatSim Card

Now that you have a spare unlocked iPhone to dedicate as your low cost global messaging phone you'll need to order the actual ChatSIM SIM card to put inside your iPhone.

You can order the ChatSim from their website at: or purchase it from Amazon

You'll be charged for the cost of the SIM card and 1 year of service. You'll pay between $20-$25 with yearly renewals running at around $12 (priced at €10 Euros).

I'd advise against ordering ChatSim cards as gifts from ChatSim's website as they'll be linked to your ChatSim account and not easily transferred to your intended gift recipient when it comes time for them to activate or renew.

What you'll get is a plastic credit card with your account number, your new mobile number (Estonia) and a SIM PIN (0000) printed on one side. The card will also have a SIM chip with 3 sizes your can punch out to fit your iPhone (newer models use the smallest SIM size).

If you've never seen your iPhone's SIM slot go get a paper clip, pull off any protective cases on your iPhone and look along the side of your iPhone for the SIM slot with paper clip hole for you to eject your SIM tray.

Step 3: SWAP SIM Cards

While all the steps can be undone, I would strongly advise that you have backed up your iPhone. If you are repurposing this iPhone I would recommend wiping all your personalized data before starting.

  1. Turn OFF your iPhone.
  2. Pull off your iPhone's case if one is installed.
  3. Look for a small SIM slot on the side of your iPhone with a place to put one end of the paper clip straight in. A small drawer should pop out. Make note of which way the card was installed (one end of the SIM has a notch)
  4. Make note of how the old Sim card is positioned in its tray. Make special note of where the notched corner is and the direction the tray fits into your iPhone.
  5. Pull out the old SIM and put it over the ChatSim card to verify what size you need.
  6. Carefully pop out the ChatSim to the specified size. There are 3 sizes to choose from.
  7. Mini-SIM for iPhone Original and iPhone 2 (3G) - note the original iPhone is not supported.
  8. Micro-SIM for iPhone 4/4S
  9. Nano-SIM for iPhone 5/5S/5c and 6/6+/6S/6S+
  10. Put the ChatSim in the iPhone SIM tray and carefully push it back into your iPhone until it is completely flush. The SIM card has a notch that matches the tray's notch. It should slide in easily and not need to be forced.
  11. Turn your iPhone back on and verify it shows the new mobile cellular wireless carrier (ChatSim uses T-Mobile and AT&T for USA coverage).

Step 4: Turn on WiFi for All IPhone Setup Steps

You'll need to turn on WiFi and connect to a HotSpot in order to get everything else on your iPhone setup. So be sure your iPhone is logged into a WiFi network before going further.

Ideally you should be setting up your old iPhone as a new setup rather than restoring from an iCloud or iTunes backup. "Set Up as new iPhone" on the ChatSim network gives you the best chance for success. You can still enter whatever Apple ID you wish to use. Apple will probably ask you to approve the use of your AppleID on this device, so be sure to go through all the prompts Apple puts up. You should get a prompt that says your carrier may charge for SMS messages used to activate iMessage. Go ahead and click ok.

To make your ChatSim iPhone is as useful as possible, setup as many Internet WiFi HotSpot access points as possible. This will allow your phone to access the Internet for all the things you can't do when you are on the message only restricted ChatSim mobile network.

On you iPhone go to Settings > WiFi > On > Choose Network

  • Home, Work, School, Coffee Shop WiFi access configured ahead of time will let your phone WiFi update as you go about your daily routines.
  • See if your Internet Service Provider at home gives you free HotSpot access. Comcast, Time Warner, Cox, Optimum and Bright House allow users to access other cable users home and business routers across the United States. Setting up Comcast's XFINITY app and network protocol gives you access to all routers named XFINITY and CABLEWIFI. If you have AT&T for internet at home you can set their mobile WiFi up and that will auto log you in at McDonalds and many other places that use AT&T.
  • Download a free WiFi Hotspot app and make sure you download a list of locations so you can easily find a location when you aren't connected to WiFi. Check out OpenSignal and WiFiMapper.

Step 5: Activating Your ChatSim Card

Now that your iPhone has it's ChatSim card installed you'll need to go to their website and activate it so that your iPhone will work on their roaming network.

To avoid confusion you should know that ChatSim has had a few variations: WhatSim, ChatSim Plus, ChatSim World. Depending on where you purchased it and when you decide to activate different plans may be available.

Goto and choose activate.

Your login and password should have been set when you purchased the cards if your bought the cards directly from them. If not go to their website and create an account.

You'll need to enter your SIM Card ID number and ChatSim's phone number, both of which are found on the back of the your ChatSim business sized card (the one with the SIM punch outs).

Telephone number Mine had the first 3 digits 372 which is the country code for Estonia.

SIM Identifier number is 19-20 digits long printed.

If you get asked for a promo code feel free to look online or use mine: CAMFAIJX for both of us to get a 1000 credit bonus (not really sure how it works, but sounds cool).

Once you activate your iPhone should receive 4 SMS text messages. Your 12 month subscription will begin.

You should verify your ChatSim web account lists the same iPhone's number found on your iPhone by going to >Settings >Phone >My Number.

Go ahead and add your new phone number to your Contacts app so that you don't forget it.

Step 6: What Is My IPhone's Phone Number?

The big reason why you want to use ChatSim in an old iPhone is so that you don't disrupt your current iPhone's setup. Some folks try to swap out SIM cards when they travel, but I've found the disruption too painful. It was far easier to setup an older iPhone as our global phone traveller than to constantly reconfigure all the settings.

Your ChatSim iPhone has a new number associated with it. The one I activated is in Estonia in Europe. You can find your phone number by going to Settings, Phone and looking at the my number field. If you haven't already copied this number into your contacts app go ahead and do so.

You'll use this phone number in your various chat apps that require a phone number.

Be sure to write this number down!

In case you are wondering about voice service. I tried calling the number, but I just get a rapid busy tone. If some of the apps let you voice call over WiFi to your ChatSim number you'll need to remember to tell your US friends to use area code to type 011 to get an International dial tone and then your phone number if they need to call you.

Step 7: Enable Data Roaming

In order for your iPhone to log into any cellular tower around the world you'll need to turn on Cellular Data roaming.

Settings > Cellular > Data Roaming

Goto Settings (the gear icon on your iPhone screen) and select Cellular.

Make sure "Cellular Data" is turned on.

Make sure "Data Roaming" is turned on.

Scroll down to "Cellular Data Network" and select it.

Change the APN (Access Point Name) to "chatsim" without the quotes and in lower case.

Leave username and password blank.

Step 8: Disable All Other Cellular Data

To avoid running afoul of ChatSim's data restrictions (5MB a day limit) so that you don't get your data access throttled or cut off be sure to do the following steps.

These steps will ensure your iPhone doesn't try to use cellular data for common items. This means you'll need to use WiFi hotspots to use most of your apps that use data.

Background App Refresh

Settings > General > Background App Refresh

Go back to your Settings and choose general, and then select background app refresh. Turn this off.

Cellular Settings:

Go to Settings > Cellular and verify the following options.

Cellular Data is turned ON. This is how ChatSim gets your your text data.

Personal Hotspot:

Settings > Cellular >Personal Hotspot

Goes without saying. Turn this off! If you just get a busy icon then this is already being disabled by the network.

Use Cellular Data For: (scroll to the bottom)

Settings > Cellular > Use Cellular Data For: Turn off ALL the apps except those that you want to use for SimChat when not connected to WiFi. This is the best way to make sure you don't get flagged for using more than 5MB of non chat data! I left Find iPhone turned on, but I'm hoping that it doesn't come close to using much data. Also remember that the apps like WhatsApp, FaceBook Messenger that you do turn on, that you'll need to be careful to only send and receive text and emoji icons. If you send or receive images, video or voice you will have to purchase "multmedia recharge" where 10 Euros gets you 2000 credits, and where each geographic region can charge a different number of credits for the data - so a short 2 minute video clip could cost you $4 or more!

WiFi Assist:
Settings > Cellular > Scroll all the way to the bottom to WiFi Assist Make sure WiFi Assist is turned OFF. This hidden Easter Eggs tells your phone to switch from WiFi to Cellular data whenever it sees that your WiFi is struggling. It is a total gotcha for folks on limited data plans!

Settings > Carrier

Make sure this is set to automatic so that ChatSim can auto log into the cellular provider in the various countries you travel to. If this isn't an option make sure your iPhone isn't still locked to it's original wireless carrier.

Step 9: Setting Up WhatsApp to Use ChatSim

Goto Apple's App Store on your iPhone.

Login with your Apple ID if prompted.

Download the "WhatsApp" app to your iPhone. iOS 6 or later is required.

Launch the app and follow the steps. When prompted for your phone number enter your ChatSim number (found on the ChatSim card, in your contact app (if you saved it in the previous steps) or in Settings >Phone >My Number.

When prompted to receive WhatsApp push notifications please choose to accept them, otherwise you'll only get notices about new messages when you are in the app.

You should receive a SMS message that gets through to your iPhone and activates your WhatsApp app.

If you let WhatsApp scan your address book it will let you know which friends are already on WhatsApp. You'll want this list of names so you know who you can message ahead of time.

Note: WhatsApp will only work on devices with a mobile telephone number. If you have an iTouch or iPad purchased without the cellular option, you aren't going to get WhatsApp to work because you don't have a SIM slot for a mobile phone number. There are some tricks for getting this to work by using their WebApp. You can read more here:

Step 10: Setting Up Apple Message's IMessage

Apple Message is the app that comes on all iOS and Mac OS X devices. Apple iMessage is the feature that allows the app to send messages free of text charges to any other Apple ID user through the data channel (similar to how ChatSim allows text chats over cellular).

To use Apple Message on your iPhone you'll need to be aware of a few things...

It doesn't work over ChatSim. I know Apple has gotten you hooked on free imessaging to fellow Apple users, but sadly ChatSim hasn't found a way to map Apple Message text data through their network.

You'll need to get your Apple friends to add WhatsApp, Facebook Messenger or the other supported Chat programs when sending you messages to your ChatSim iPhone when you are out and about.

When you are connected to WiFi you can still use Apple iMessage, but you can't send SMS text messages to non Apple ID folks like you could when your iPhone was tied to wireless carrier.

Here are some Apple Message WiFi Tips:

Make sure all your Apple iPhone friends have their name, emails and phone number saved to your Contacts app. If you just type their number into Apple Message you'll get a delivery failed message, but if you type their number and see their contact show up in blue lettering and click the person then the message will see the Apple ID and route it to them over WiFi.

Settings > Messages

Make sure in Settings you select Messages and verify you have iMessages turned on. If it is OFF nothing will work. Makes sense, but more often than not it is off (and the reason why wireless providers soak their users with expensive SMS fees). I noticed that I get a "waiting for activation" message under iMessage. I;m wondering if Apple Message is trying to send a SMS activation message that SimChat is unable to pass along like they do with other supported apps.

While you are in here I would go ahead and turn on Send Read Receipts so your Apple Message friends can see if you've gotten to a WiFi hotspot to even receive their message yet.

Turn off "Send as SMS" since with SimChat, SMS isn't supported anyways, so why have the phone wasting time trying to send it.

"Send & Receive" should be showing the email address you used to register your Apple ID with. Go ahead and add any other email addresses that you want associated with your Apple ID (maybe leave your FaceBook ID for FaceBook Messenger and your Gmail ID for Google Hangouts to make sure those messages can go over SimChat's partner network).

Step 11: Setting Up Facebook Messenger

Download the Facebook Messenger App from the App Store.

Log into the Messenger App while you are still on WiFi.

Enter your Facebook email and password. You should get a verification message and be set to go. Be sure to test sending messages without WiFi to verify it works.

The nice thing about Facebook Messenger is that ChatSim will allow you to send unlimited text and emojis. If you try to send or receive calls, photos or videos you won't be able to until you have WiFi access.

For many folks they'll often have more friends already on Facebook than any other messaging service.

Facebook Messenger also allows you to check your messages on the web. You can login at:

Step 12: WiFi Calls Through Your Ooma Home Phone

If you still have a landline at home and want to be able to use your iPhone to send and receive phone calls through your home phone number while you are traveling abroad you should check out Ooma.

It is a Voice Over IP phone system that plugs into your home router. You can use your normal landline phones at home, but while you are traveling you can use the Ooma app and set it up to make and receive calls as if you were at home.

On our kids SimChat iphones we let them use Ooma to make phone calls so that their caller ID will show up as our family phone number, instead of some strange international call!

The caveat is that SimChat doesn't know anything about Ooma, and your iPhone will only be able to use the Ooma app while you are connected via WiFi.

Step 13: Interesting Notes

Some additional notes from my testing...

Emergency Phone Function

When you go to use the Phone Call button it looks like ChatSim is able to block the keypad and voicemail functions. The only exception I found was that when I typed in 911 it looked like it was going to complete the call. I'm guessing that in the US all cellular providers have to grant emergency services.

Cellular Service Providers

In the US it looks like ChatSim uses AT&T and T-Mobile for their cellular data chat functions. At 10 Euros a year they can't be paying T-Mobile much to carry the text data. If you can limit yourself to just text chatting when you aren't on WiFi you are paying less than 3 cents a day!

Photos as Text based Images

I'm old enough to remember computers that only had dot matrix characters and that an entire culture of ASCII Art flourished. If you want to send a photo over SimChat you can use a simple app like Asciilizer or Ascii Booth to convert a high contrast photo you've taken into ASCII characters, click send to email and then select all, copy and paste it into your WhatsApp or other Chat software.

Step 14: Choosing ChatSim Compatible Apps




Facebook Messenger - Silicon Valley based Facebook with 600 million users.

WeChat - China based Tencent with 600 million active users.

Kik - Canadian startup with 240 million users. Popular with American teenagers.

Line - Joint Japanese and Korean venture with 700 million users.

Hike - Based in India with 70 million users. You can chat and share files locally without internet or cell phone service within a 100 meter radius.

Kakao Talk - South Korean app with 140 million users. It is popular across Southeast Asia.

QQi -China based Tencent with 750 million users and supports 6 languages English, French, Japanese, Spanish, German and Korean).

Step 15: Offline Google Maps

Google now allows you to save offline Google Maps! This is great for ChatSim users who couldn't otherwise access the map unless they were connected to WiFi.

Install the Google Maps App.
Log in to Google Maps.
From the menu options choose Your Places
Choose Offline Maps > View and Manage
Choose Save A New Offline Map

Note - Offline maps don't have the online navigation option, it's like a paper map with zoom. Secondly offline maps expire in 29 days so take this into account as you manage your globe trotting with ChatSim.