Companies are getting a hard lesson in how to tactfully do business in the post-Brexit U.K after British Airways sparked a Twitter backlash for urging overseas travellers to benefit from the drop in sterling sparked by the result of Britain's EU referendum.

A tweet from the airline's official account Monday, apparently aimed at U.S. travellers, said "Your dollar has never gone further, and with our amazing 3-day sale, you can see even more of London!"