General IMEI questions

maxmxnmx · Sep 21, 2006

Hi Everyone

I have some questions about IMEI numbers on the phone, if you know anything please help me understand:

I usually buy phones on Ebay - on my last purchase I found out that the phone was either stolen from someone or someone found it as it had some SMS stored and also some video files- I returned the phone to the seller because I wasnt sure if a network or police can block this phone on IMEI number or if it has been reported stolen. Is this possible?

If my phone is lost or stolen can I report is stolen and the network blocks it?

Can the network provider trace the phone using the IMEI number?

What is the main purpose of IMEI?

Thanks for your help.

pazzini · Sep 21, 2006

If you are from the UK then yes the network can block the mobile and will be able to trace it when it is switched on. (as long as they have the relevant information from the original owner)

If you are from the USA I beleive that they do not block there phones if reported stolen/lost.

maxmxnmx · Sep 21, 2006

Last month my phone was lost/stolen but the network said that they won't be able to block it with IMEI? But a freind of mine said they can...

Confusion!!!!

JoeGons · Sep 21, 2006

Too much to explain.
Have a look here.

http://en.wikipedia.org/wiki/International_Mobile_Equipment_Identity

maxmxnmx · Sep 21, 2006

But do NETWORKS in the UK follow the Black list? and do they really block the missing phones? Becuase O2 told me that they can't block it.

pazzini · Sep 21, 2006

It is true that here in the UK that a network can barr/blacklist the mobile, the muppet you spoke to at O2 does not know what they are talking about. Call them up agian and talk to someone with a brain.

maxmxnmx · Sep 21, 2006

Yes, but if the phone I got from eBay is stolen from someone and the network blocks it do I have anyway to unblock it? I will call O2 again right now and speak again.

pazzini · Sep 21, 2006

Yes, but if the phone I got from eBay is stolen from someone and the network blocks it do I have anyway to unblock it?
Click to expand...

NO!

maxmxnmx · Sep 21, 2006

Will the phone I have work outside the UK if its blocked in the UK?

pazzini · Sep 21, 2006

Will the phone I have work outside the UK if its blocked in the UK?
Click to expand...

NO!

maxmxnmx · Sep 21, 2006

Thanks!!!! That helps!

pazzini · Sep 21, 2006

Anytime.

pazzini · Sep 21, 2006

Blacklisted or Barred Handsets

What is it all about???
A phone may be blacklisted (or barred) for many different reasons, but the most common reason is that it has been reported either lost or stolen! It is only the networks (Orange, T-Mobile, O2, Vodafone etc) that have the facility to blacklist a handset.

If you are unfortunate enough to either lose or even worse have your phone stolen you should report it to your service provider (your network) immediately! Your service provider can then blacklist the handset so that it can no longer be used to make or receive any calls. The networks do this by adding your phones serial number onto a national blacklist database (Central Equipment Identity Register). Effectively the handset becomes absolutely useless and the thief is in possession of a pretty paper weight! FPRIVATE "TYPE=PICT;ALT=Smile" )

So How Does Blacklisting Work?
Every mobile phone has a unique serial number. This serial number is called the IMEI number (International Mobile Equipment Identity). It can normally be found underneath the phones battery and it is 15 digits long.

Now each time you switch your phone on or attempt to make a call the network systems check the IMEI number of the handset you are using. At this point the IMEI number of your handset is cross referenced with the Central Equipment Identity Register. If the IMEI number of your handset is on the CEIR then the network will either:

1) Refuse to send a signal to your phone (No signal strength at all)

2) OR WILL supply a signal but will not allow any outgoing or
incoming calls.

If your IMEI number is on the CEIR your handset is blacklisted and therefore useless. By spreading the word that "stolen handsets will not work" it is hoped that street crime can be reduced!

How to Check If Your Phone is Blacklisted!!
Different networks blacklist handsets in different ways:

Orange & O2:
If you place an active orange or
O2 sim into a blacklisted handset you
phone will not show any signal strength
at all! If the handset is a Nokia then a
"SIM card registration failed" message
will also be displayed. If your handset is an
Ericsson then an "Invalid Mobile" message
will be displayed. For most other manufacturers
the handset will simply show no signal!

Vodafone & T-Mobile
If you place an active Vodafone or T-Mobile sim into a blacklisted handset, the phone will appear to function perfectly UNTIL you try to make an outgoing call. When you try to call out from the handset you will hear a sequence of beeps and then the call will be dropped!!

Unlocking & Blacklisting, is there any Connection?

The answer is that there used to be a connection before O2 and Vodafone started blacklisting handsets! Orange and T-Mobile have been blacklisting handsets for a long time (It is only recently that O2 and Vodafone also started blacklisting handsets).

NB Orange & T-Mobile always lock their handsets!(e.g. an Orange handset will only accept an Orange sim and will not accept an O2, Voda or T-Mobile sim)

So if you reported your Orange or T-Mobile handset missing to your network it became barred/blacklisted! BUT it was only barred on your home network. Therefore unlocking the barred handset would enable it to work on every network except the one it was originally locked too! Therefore the phone still had some commercial value, as it would function on at least 3 out of the 4 networks.

It wasn't long before Orange and T-Mobile began to combine their individual blacklist databases. Therefore a phone barred on Orange was also barred on T-Mobile and vice versa. Even at this point the barred handset could be unlocked and used but only on 2 out of a possible 4 networks (O2 & Vodafone).

The government eventually stepped in and forced O2 and Vodafone to update their systems and introduced the CEIR. Now that all the networks share a central blacklist database, even if a barred handset is unlocked it still remains useless on ALL UK networks!

How Do Criminals Get Around The Blacklisting Scheme/CEIR?

So now that handsets are blacklisted on all networks what do the criminals do to get around this? They find ways to change handset IMEI numbers! Amazingly it is only recently that the altering/changing of IMEI numbers has become illegal! Home Secretary David Blunkett introduced a new law making re-programming IMEI numbers punishable by up to five years in jail. View / Download the Mobile Phones (Reprogramming) Act 2002 here! This new law became active on the 4th October 2002 . (this new law does not effect handset unlocking).

Never the less it is possible to change IMEI numbers on certain handsets. So if an individual obtains a blacklisted handset, they can change the IMEI number and the handset will then work again!!

In my opinion the responsibility now lies with the handset manufactures. They need to make it as difficult as possible to change IMEI numbers. To be fair some manufactures are doing their bit (but some are not!). For example Nokia's older DCT 3 range of handsets have been well and truly cracked. Anyone that searches the Internet for a short period of time would be able to find an IMEI change solution. BUT Nokia's new DCT4 range of handsets remains un beaten with regards to changing the IMEI. This is largely down to the type of memory used to store the IMEI number. Nokia have chosen to use OTP (one time programmable) memory, which by its very name indicates that data cant be over written. (unless you change the UEM/memory chip - technically this is out of the realms of most criminals!)

The criminals do have an alternative to changing IMEI's, and this is to send the barred handsets overseas! The blacklist database (or CEIR) is only used by the UK networks. Therefore a handset that is barred in the UK will work fine in a different country! Apparently a large number of UK barred handsets find themselves in Italy, Spain and France etc.. The Barred handset works fine in any country outside the UK!!

The solution to this exporting problem is simple. Rather than a national database the mobile industry is now looking to build an international database. If/when this is introduced blacklisted handsets will not work anywhere in the world! (The international database idea sounds good! But it does have obstacles to overcome, as many African networks claim that it would be too expensive to upgrade their equipment to support such a system)
Click to expand...

Retro_rc · Sep 21, 2006

A stupid question please

can we change the imei

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