UK consumers are having to remember an increasing number of security codes and passwords, and are taking risks with this key information, a survey claims.
One in four consumers said they keep Pin details in their wallet
According to financial advertising agency @www, the average adult needs 15 different security codes and passwords.
Almost one in ten of us has to memorise information for more than 50 accounts.
With so many numbers floating about, some people are writing down their details, or using the same words and numbers, increasing the risk of fraud.
Sixty percent of those questioned in the survey admitted using the same numbers or words for multiple accounts.
The banking industry warned consumers they must keep such data secure.
Barnaby Hobbs, UK general manager of @www, said people are struggling to cope with the "exponential" growth in the number of companies requiring personal security data.
"We are drowning in Pin numbers and security codes," he said.
"Whilst companies have standardised the requirements to access their sites, most usually require a username and a password, and most people have simply too many to try and remember them without writing them down.
"Too many people are now writing their numbers down in unsafe locations," he added.
The survey found that eight percent of those questioned had codes written down within ten feet of their computer, whilst almost a quarter kept them in their wallets or bags.
Two thirds of those who carried their Pin codes with their cards did take the precaution of jumbling the numbers up, but the majority who did so simply reversed the digits.
People typically need to learn a new password or pin every three months, Mr Hobbs said.
Those surveyed also highlighted difficulties with back-up security questions used to verify Pins or passwords.
Many companies offer a range of prompt questions, such as your mother's maiden name, first school attended or pet's name.
But more than a third of those questioned admitted they struggled to remember which they had selected, meaning account access was regularly denied.
'Belt and braces'
Jemma Smith, from the UK payments association Apacs, said the onus was on consumers to ensure their security data is kept safe.
"The belts and braces advice is that you should use different pins and passwords for every card and account you use," she said.
"However, if you can't do this and intend to write down your password or Pin it would always be less risky to use the same pin or password for them all," she added.
She warned of the dangers of storing Pins and other information in a wallet or next to a computer where they could be found.
"If you do write down your Pin or disclose it and a thief uses it, your bank is within their rights to hold you liable for any fraud losses that are incurred.
"Equally this applies to your online or phone banking security information," she added.
Anyone who thinks a Pin or password has been compromised is advised to contact their bank or card company immediately and change them.