# 'Chipped' cellphones

**URL:** <https://boards.straightdope.com/t/chipped-cellphones/102816>\
**Category:** Factual Questions\
**Created:** [April 10, 2002, 12:35pm UTC](https://boards.straightdope.com/t/chipped-cellphones/102816 "2002-04-10T12:35:07Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![jjimm](https://avatars.discourse-cdn.com/v4/letter/j/ba8739/32.png) [@jjimm](https://boards.straightdope.com/u/jjimm)\
**Post date:** [April 10, 2002, 12:35pm UTC](https://boards.straightdope.com/t/chipped-cellphones/102816/1 "2002-04-10T12:35:07Z")

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Here in Ireland there are two major cellphone networks: Vodafone and Digifone. Each sells handsets from the major phone manufacturers when you open a cellphone account. Problem is, if you have a Digifone SIM card, it won’t work in a Vodafone phone, and vice versa. The handsets have been ‘chipped’ in some way. Does anyone know how this is done - hardware or software - and if it is reversible?

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**Author:** ![stockpuppet](https://avatars.discourse-cdn.com/v4/letter/s/5f8ce5/32.png) [@stockpuppet](https://boards.straightdope.com/u/stockpuppet)\
**Post date:** [April 10, 2002, 1:04pm UTC](https://boards.straightdope.com/t/chipped-cellphones/102816/2 "2002-04-10T13:04:58Z")

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You mean “Provider Specific” phones. This is done for the phone companies by the manufacturers. Even if you get a “sim free” phone ie just the handset it will only (probably) work with the phone company it was intended for. We had this situation recently and had to order a “sim free sim free” phone. which is apparently the name that is given to a phone that will work with any network.

In the UK in the 90’s “Chipped” meant a phone that had had it’s sim replaced - they used to be non-removable.