He has been billed for downloading more than 9, 000 megabytes of data, despite having a monthly download allowance on his account of only 750 megabytes.

BBC: Mobile phone ?6,875 bill for decorator Chris Wilson

If selected, a user's data allowance will automatically be increased and their account charged.

ENGADGET: Tep Wireless unveils European-wide hotspot rental service for $5-a-day, 1GB of data included

Nationwide for Business Data Packages and Plans allow a business of any size to create their own shareable data allowance with the simplicity of managing a single account.

FORBES: Verizon To Begin Offering Share Everything Plan for Small Businesses On January 24

Now there are about 19 million Isa account holders in the UK, with five million using the full allowance each year.

BBC: Isa limit rises for the over-50s

These cards loaded with money but typically not linked to a bank account can hold everything from financial-aid funds to an allowance.

WSJ: Companies Push Prepaid Debit Cards Catering to College Students

The trial, which became known as the "Mensalao" or the "Big Monthly" allowance, was seen as a key test of Brazil's ability to hold its politicians to account for corruption.

BBC: Brazil prosecutors investigate ex-President Lula