COVID-19 Travel Advisory: Stay up to date with the latest on the coronavirus pandemic.   Learn More >

What is an unlocked phone?

Old Apr 21st, 2007, 06:10 PM
Original Poster
Join Date: Sep 2003
Posts: 2,071
What is an unlocked phone?

This is not really a travel question, but it is travel related. And because people here, as a collective, seem to know pretty much all about everything, here it goes:

What is an unlocked phone and where do you get it from? I keep reading about them and about SIM cards…but have no idea what I’m reading about. It seems that an unlocked phone needs a SIM card – what’s that?

We are going to Ireland in the summer, and would be nice to have a cell phone available. So, where do I start? What would we need?

Sorry for all the stupid questions I asked lately. Thanks
xyz99 is offline  
Old Apr 21st, 2007, 06:48 PM
Join Date: Jan 2003
Posts: 2,945
If you do a search, you will find a great deal of information about cell phones on here.

Basically, cell phones acquired from most of the companies in the US are "locked" so they can only be used with a particular company.

When a phone is "unlocked" it can be used with any company that supports its technology. Unlocked phones are sold on ebay.

A sim card is a piece of hardware, a small plastic card, that fits in some cell phones to make them work with a particular company's service. If you have an unlocked cell phone, you can substitute the sim card from one company with another, including when you travel overseas.

If you buy a cell phone to use overseas, you basically want an "international" phone, one that has either quad band or tri band capabilities, preferably the quad band. That is because most places overseas operate on two frequencies that are different from the two frequencies used in the US.

You should be able to pick up a phone on ebay for about $50. A sim card in Ireland will cost you about $25. It comes with a certain amount of talk time built in. When you exhaust that, you can "top it off" adding more time.

Finally, if you already have cell service from someone like Cingular you may already have a tri band or quad band phone. If that is the case, you can contact them to get the information to allow you to get the phone unlocked before your trip. Then all you need to do is buy a sim card when you get to Ireland.
Jack is offline  
Old Apr 21st, 2007, 07:01 PM
Join Date: Feb 2006
Posts: 179
In addition to what Jack has just said, IF you have phone service with Cingular or T-Mobile and a quad band phone, you can request the unlock code so you can use it for international travel. It took a while for Cingular to get mine to me, but they did send it. I have used it with a Vodafone SIM card (Subscriber Identity Module) in Italy.

Those two companies use the same technology used in Europe. The other carriers, Verizon, Sprint, etc don't use the same technology that is used in Europe.

You can use your Cingular Quad band phone in Europe.... you'll just pay a lot more than you will if you buy a SIM card for the country you are visiting.
Fibonacci2358 is offline  
Old Apr 21st, 2007, 07:03 PM
Join Date: Feb 2006
Posts: 179
I should add that you can use your Cingular phone with your current US SIM card'll just pay more....
Fibonacci2358 is offline  
Old Apr 21st, 2007, 07:11 PM
Join Date: Sep 2004
Posts: 45,322
I have Cingular Quadband phone and as I understand it you have to sign up for the plan to use your Cingular phone in Europe. Or if you can get Cingular to unlock your Cingular phone then yes you can buy a SIM card in Europe which makes the cost per minute quite a bit inexpensive.
LoveItaly is offline  
Old Apr 21st, 2007, 07:20 PM
Join Date: Jun 2004
Posts: 1,647
Here's a link to the most recent thread:

Itallian_Chauffer is offline  
Old Apr 21st, 2007, 08:13 PM
Join Date: Nov 2006
Posts: 8
I'd suggest checking out It has been a lifesaver for me, more detailed questions and answers... Good luck!
mercedespony is offline  
Old Apr 22nd, 2007, 08:27 AM
Posts: n/a
I've bought a mobal phone -- web site at -- which has advantages and disadvantages. (I have no connection with that company except as a customer.)

For $49 you can get a phone that works in most countries but not the US, for $99 one that works in more countries including the US. You get a UK phone number with voice mail. When someone calls the UK number, your phone rings wherever you are in the world, or goes to the voice mail.

The disadvantages are, first that people in other countries who want to call you have to call the UK number. For instance, if you are in Athens and someone else in Athens want to call you, they have to call the UK number. You don't get a number in the country you are traveling in, unless you are traveling in the UK. And per minute charges are high.

The advantages are, first that there is no cost at all after you buy the phone unless you use it. There is no contract or minimum use required. You have to pay for incoming calls and voice mail, but when you are not traveling, you can turn off the phone and disable voice mail, and you will then have no charges at all. Also, a great advantage is that you can give people at home, as well as your airline and travel agent, that one UK number, and they will be able to contact you wherever you are in the world.

All in all, I think this phone is a good choice for people who don't intend to use a phone overseas except when really necessary, and who put a high value on people being able to contact them easily anywhere they travel -- you only have to give them one number.
Old Apr 22nd, 2007, 08:33 AM
Join Date: Jan 2003
Posts: 5,271
...BTW, since it's a UK (actually O2 UK service) number, you won't pay to receive calls while in the UK.
xyz123 is offline  
Old Apr 22nd, 2007, 08:57 AM
Original Poster
Join Date: Sep 2003
Posts: 2,071
Jack, xyz123 and everybody in-between,
THANK YOU! This is great info, exactly what I was looking for. We don’t have Cingular or T-Mobil, so we need to purchase a special phone for Ireland.

I will do more research and compare the unlocked phone + SIM card vs the mobal one. Both seem to have advantages and disadvantages, so need to figure out what’s more important to us.

And of course, I will check slowtrav, too.
Thanks again.

xyz99 is offline  
Old Apr 23rd, 2007, 08:13 PM
Join Date: Sep 2003
Posts: 181
If you are just going to Ireland it may pay to wait until you arrive and then you can purchase a phone set up for that country. Usually you can buy the prepaid mobile plan which includes the actual phone and some free time. This phone would be good for making and receiving calls all over ireland. With the proper international phone card you can use it to call the US. If you travel to other European countries and intend to stay for any length of time you can buy a SIM to use in those countries. I have an English friend who brings her UK phone to Spain and inserts her Spanish SIM card when she gets there.
Raydotman is offline  
Old Apr 23rd, 2007, 08:27 PM
Join Date: Feb 2003
Posts: 1,559
Do you have to pay Cingular for the unlock code? I see some websites for getting codes, including eBay, and they all charge for the codes.
vivi is offline  
Old Apr 23rd, 2007, 09:53 PM
Join Date: Aug 2003
Posts: 9,922
Just to clarify a little further (well, hopefully): the cellphone technology that employs SIM (subscriber interface module) cards is called GSM. It's used in most countries of the world. It's also used in the USA and Canada, but the dominant cellphone technology there is not GSM but CDMA, which is probably what your current network provider uses.

As other posters have explained, even if your US network is GSM, it will use different frequencies from those used in most other countries (850 & 1900 Megahertz vs. 900 & 1800 MHz, for the record). A tri-band or quad-band phone will work almost everywhere except, I think, Japan, which has its own unique system.

GSM coverage in parts of North America can be patchy. The main GSM carriers, e.g. Cingular and Verizon in the US and Rogers in Canada, should publish coverage maps.
Neil_Oz is offline  
Old Apr 23rd, 2007, 11:25 PM
Join Date: Jan 2003
Posts: 5,271
Ah Neil...

Verizon is not a GSM carrier...the GSM carriers in the USA are Cingular and T Mobile USA..otherwise you nailed it well.
xyz123 is offline  
Old Apr 24th, 2007, 01:42 AM
Join Date: Jan 2004
Posts: 2,260
A locked phone lives a monogamic relation with his/her SIM.
An unlocked phone lives a poligamic relation with whatever SIM he/she founds during his/her lifetime.

I kept intentionally the "his/her" because I don't know the sex of the device. My educated guess is that locked phones are male and the unlocked ones are female. You know, the "La donna è mobile" thing

lobo_mau is offline  
Old Apr 24th, 2007, 01:48 AM
Join Date: Jan 2007
Posts: 332
Please be aware that even if you do not contact Cingular in advance to "unlock" your phone for use overseas, you will still be charged if you check voicemail.
jewela is offline  
Old Apr 24th, 2007, 03:01 AM
Join Date: Jan 2003
Posts: 5,271
There seem to be some misconceptions here...

If you are using international roaming on either cingular or T Mobile USA, you need not unlock the will be using the same sim card, same phone number, same account as at home. The only thing different is you will pay exhorbitantly high rates...of course if you just use the phone for a call or two and to receive calls in an emergency, it isn't going to break you. All you need from the phone is that it have at least one (900 or 1800) of the European frequencies.

If you are buying local or international sim cards, that's when you need the phone to be unlocked. Locked or unlocked refer to the ability to use only the sim card of one company (locked) or any sim card (unlocked)...also if you are going the local sim route, you have to be more concerned with frequency and you really should make every effort to have a phone that has both European frequencies as some carriers are more dominant on one frequency than others. For example, much of the coverage on O2 UK is on 900 (it does have a moderate amount of 1800 coverage but 1800 coverage n o2 UK is nonesistant in some areas of the UK) so if you have the typical American tri band (850/1800/1900) necessary on Cingular as Cingular has a lot of 850 coverage in the USA not as important on T Mobile USA as T Mobile USA is predominantly 1900 coverage so if your home USA carrier is T Mobile USA, for the most part you'll be fine with a tri band with 900/1800/1900 (although T Mobile's coverage especially in rural areas sometimes necessitates you roam on another network which is predominantly 850; hence recent tri band phone sold by T Mobile USA are 850/1800/1900 and lack 900) if you're using your unlocked USA tri band phone from Cingular in the UK, you don't want an o2 sim...but T Mobile UK or Virgin Mobile which use T Mobile UK towers will be fine as T Mobile UK operates predominantly on 1800....

I know Robespierre, much too wordy...perhaps you can make the point in a more concise way.
xyz123 is offline  
Old Apr 24th, 2007, 08:46 AM
Join Date: Apr 2007
Posts: 222
vivi, no you do not have to pay Cingular to unlock the phone. They will unlock after 90 days of service with good standing. Tmobile is the same. I received my unlock codes from cingular in 4 days from the day I requested it.
mrcamp is offline  
Old Apr 24th, 2007, 02:35 PM
Original Poster
Join Date: Sep 2003
Posts: 2,071
We have Verizon, so it seems that our options are either
1) buy an unlocked phone on eBay and when we get to Ireland) and an Ireland SIM card. Based on prior posts, it seems that would be about $50 + $25 = $75.
2) buy (when we get in Ireland) a cell phone, as Raydotman suggested. Any idea how much this costs? Can we get it at Shannon airport?

We intend to use this for emergencies – call the B&B if we’re going to be late, call for assistance in case our car breaks on some side-road, things like that.
xyz99 is offline  
Old Apr 24th, 2007, 02:39 PM
Join Date: Jan 2003
Posts: 5,271
-24 (123 - 99)...

Have you considered the mobal alternative...that is if you're only going to make a few emergency calls? Probably the easiest although not if you really intend to use the phone the best alternative?
xyz123 is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Do Not Sell My Personal Information