The Observer was one of more than 7,000 BT customers affected by a Broadband blackout on Monday.
A fault with hardware equipment at the company's Carmarthen Exchange resulted in loss of internet and email connections for most of the day.
The problem - which arose at 10.24 am - did not however affect any telephony services.
BT spokesman Jason Mann said that engineers worked throughout the afternoon to replace the defective equipment in the exchange.
"We worked as swiftly as possible to restore services," he said.
"Although the majority of users who could not access their connection were in Carmarthenshire, there were a number in the Tenby area who also had problems."
All customers had their internet connections restored by 7.30 pm.