Wales was the first part of the UK to introduce a mandatory charge for carrier bags in October 2011.

BBC: New Wales carrier bag-style charges 'a possibility'

The alerts are free, but your phone carrier may charge for the text messages.

FORBES: Free Online Alerts Can Help Credit Card Customers

Alternatively, consider what your home carrier would charge you if you didn't have a data roaming plan in place.

ENGADGET: iPhoneTrip SIM rental review: the best way to keep your smartphone connected while abroad

Earlier this month Samoa Air made headlines for becoming the first carrier to charge passengers according to their weight.

BBC: Should heavy travellers pay more?

The Welsh government also revealed it had received a total of 12 complaints relating to the carrier bag charge through its formal customer complaints policy.

BBC: News

The Welsh government says it will "investigate the opportunities and benefits that could be derived from building on the success of the carrier bag charge, by extending to other products and packaging".

BBC: New Wales carrier bag-style charges 'a possibility'

The refund typically comes as a voucher from the carrier and some charge a processing fee.

WSJ: Summer Travel��Where the Deals Are ��and Aren't

The Northern Ireland Executive will bring forward legislation later this year to introduce a 5p charge for single-use carrier bags in April 2013.

BBC: Plastic bags: Welsh government urges charges for rest of UK

Back then Thai Airways, the country's flagship carrier, was in charge of the duty-free operations at Bangkok's old Don Muang International.

FORBES: The Kingdom and the Power

Retailers must now charge shoppers at least five pence for each new single-use carrier bag.

BBC: Northern Ireland's new five-pence carrier bag tax