JT will begin switching off its 3G services from January 2025.
The telecoms company says that just 5% its customers use the technology.
It has confirmed its intention to begin phasing out the network across the Channel Islands in just over 12 month's time.
3G was introduced in the islands in 2009, but has been superseded by 4G and, soon 5G to support mobile calls and internet data.
JT says its giving a year's notice to 'ensure a smooth transition' and so that people without modern mobile handsets can switch to the right device for them.
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