A campaign in the UK against retailers forcing travellers to produce boarding passes before processing transactions in airports has led to a number of key-retailers clarifying their practises.

The Independent (London) started a campaign to highlight the fact that there are no rules requiring boarding passes to be produced at airport checkouts.

The reason why these documents are requested and scanned is so that companies can avoid paying VAT on transactions carried out by those travelling outside of the EU.

Under European rules companies do not need to pay taxes on these sales - but they need to scan the boarding pass data to show that the goods are being sold to people leaving the EU. 

Always refuse to show your boarding pass to retailers at Airports.

— Duncan Bannatyne (@DuncanBannatyne) August 12, 2015

Retailers have been criticised for not passing these savings on to customers.

Ireland's Aer Rianta International (a subsidiary of daa which manages retail operations at Dublin and Cork Airports) says that travellers are only obliged to present boarding passes when buying tobacco and alcoholic products. Otherwise they may be requested, but you are not obliged to present the pass.

The Competition and Consumer Protection Commission has called for greater clarity from Irish retailers, saying that they need "to be very clear with their customers as to the circumstances where they collect VAT on behalf of the State or where VAT is not charged."

Companies pocketing VAT savings has been branded a "scam" by The Independent. There has been confusion across the UK's airports as flyers have refused to have their passes scanned.

WHSmith, Dixons and Boots have issued new directives to staff clarifying that passengers are not obliged to share their flight details at the checkout.