Confusion over the introduction of chip and pin could lead to an increase in bank card fraud. From today most bars and restaurants will not accept card payments with a signature. Instead customers must know a four-digit Personal Indentification Number to process their transactions. A new study of 3,000 card users found that half were unable to recall their PIN number and were planning to write it down or tell their partner. Shirley Woolham of security firm Card Protection Plan, which conducted the poll said this possible lapse was “incredibly worrying”.