A cautionary tale for those tempted by Apple

There is a long trail of British technology companies that learnt the dangers of getting into bed with Apple the hard way. Any deal that earns its owner a cut of every iPhone sold should be a golden ticket: not only did Apple sell around 200m of the things last year, but the innovations in the iPhone often make their way down the smartphone food chain to devices made by rival manufacturers seeking to cut Apple’s lead.

Britain’s most famous tech success story, Arm Holdings, capitalised on designing low-power microprocessors for the iPod, extending that to the iPhone and then the rest of the smartphone world to become a world leader.

But while Arm’s lead in designing smartphone chips is as strong as ever, many of Britain’s Apple suppliers have not fared so well. Edinburgh’s Wolfson Microelectronics, which made audio chips for the iPod, grew to rely on business from Apple before it was dropped...