Students are being warned to watch out for criminals trying to recruit them into money laundering scams - as Barclays says nearly a third (30%) of money mules reported to it last year were aged under 21.
Fraudsters may ask people to receive money into their bank account and transfer it elsewhere, keeping some of the cash for themselves.
People receiving such approaches may not realise this makes them a money mule involved in laundering cash, which is a crime.
Barclays said its data suggests instances of under-21s being recruited as money mules has nearly doubled, with a 97% increase, between 2016 and 2018.
Students struggling to balance their budgets may be particular targets, with promises of being able to make some "easy" money.
Ross Martin, head of digital safety at Barclays, said: "We know criminal gangs are ruthlessly targeting cash-strapped students on campuses across the UK, with the aim of tricking them into laundering their dirty money.
"Worryingly, we've seen a sharp increase in the number of student money mules who unwittingly allow criminals to access their bank accounts, unaware that the money flowing in and out is often connected to serious crime.
"It is vital that all students are aware of the risks and can spot the warning signs when they think they are in danger."
Here are some tips from Barclays:
1. Do not give away any of your bank account details, unless you know and trust the person receiving them - and never let anyone else access your account.
2. Be cautious of unsolicited offers of easy money as this is a common tactic used by criminals to recruit money mules.
3. If you are concerned, tell someone you trust, whether it is a parent, tutor or friend.
4. Take time to think. Remember that letting someone else use your bank account is a potentially serious crime which could damage your financial future - is it worth it?
5. Remember the simple rule of thumb about offers of easy money - if it looks too good to be true, it probably is.
