"For five days - from 5am GMT Wed 25th to 10am GMT Sun 30th - we're giving away completely free calls to the US, no strings attached," Localphone said in an email.

Users can call from their existing landline or mobile using the companies Direct Dial and Calling Card products, or from their PC, laptop, or VoIP-enabled mobile device including Apple and Android devices using third party applications such as like Fring and Nimbuzz with a Localphone VoIP.

"As the world's economies start the slow march of recovery we feel it's important that all businesses do what they can to help ease the pressure we've all been experiencing," said Paul Cusack, Localphone CEO.

"This Thanksgiving promotion will help get the word out about our low-cost calling services, and hopefully bring families and friends together that would otherwise have struggled to keep in touch this year."

Localphone point out the service is Mac compatible.