Telecoms provider JT has announced maintenance work across its landline network.
It will take place between 1am and 7.30am for 3 weeks on 28 October, 4 November and 11 November.
Customers will be unable to make landline calls for a period of 3-5 seconds, but it may take up to 3 hours for inbound calls to landlines to return to normal.
JT says the work has been planned to minimise disruption to customers, and that mobile and broadband will be unaffected.
The company says that any customers without a phone will be able to request a loan mobile from the company to use during the outages by contacting them on 882882 before October 14.