Telefonica and mobile identity firm TeleSign announced a new service for banks and credit card firms that helps verify travellers’ card payments.

The service, which is called Travel Alerts, works with the location of a user’s mobile phone to provide an alert to a participating financial institution.

The card firm or bank uses the location-based information to help verify any transactions made by their customer in that country.

A user needs to opt-in to the scheme by supplying their mobile number to their bank or credit card provider.

Telefonica and Telesign said trials showed a significant reduction in the number of customer calls advising banks and card firms of their travel plans. Answering such calls carries a cost for financial institutions.

US bank MBNA ran an 18 month trial of the service, and said it saw a “marked reduction” in operational costs because of less customer calls, as well as a positive effect on card approval rates.

Telefonica and TeleSign are also talking with other fraud prevention specialists, additional operators, as well as banks and credit card companies to spread the service. Telefonica described it as “a cross carrier initiative” that is expected to roll out to other operators in the second half of 2015.

The operator also hopes to turn Travel Alerts into an industry standard.

However, it is not the first such service. MasterCard and Syniverse announced at Mobile World Congress in 2014 they were piloting an opt-in service that enabled card transactions for users only when they have their mobile device switched on abroad.