Around one in five (18 per cent) people across the UK have fallen victim to a finance scam - such as a fake pension or investment opportunity - in the past year, research for Citizens Advice indicates.
The charity estimates that nine million people have been affected.
More than two-fifths (43 per cent) of people who were scammed had to borrow or increase their debt in some way to get by, and nearly a quarter (24 per cent) had to turn to friends or family for financial help. A fifth (20 per cent) had to take on additional jobs or shifts at work, the Savanta survey of more than 2,100 people found.
As part of its Scams Awareness campaign, Citizens Advice wants to help people stay safe by exposing scammers' tactics.
It said the most common financial scams included fake debt advice being offered on social media, scammers posing as a 'friend in need', pension scams, investment scams and parking QR code scams in which stickers with bogus codes are placed over genuine ones at car parks.
QR code scams direct people to fake payment websites where their personal and financial information is stolen.
More than three-quarters (76 per cent) of all types of finance scams were carried out through social media sites, according to the research, conducted in August.
One man contacted Citizens Advice after falling victim to trading and cryptocurrency fraud.
He had watched an online tutorial video about a legitimate trading system, but alongside it was an advert leading to a fake platform run by scammers, the charity said.
The man said: 'After I started putting money into the 'trading system', I immediately got aggressive phone calls several times a day, saying: 'You've got to keep trading or you'll lose everything.' Any requests to withdraw my money were ignored.
'It's a very unpleasant, stressful, intensive and coercive experience. I was frantic, traumatised and couldn't face telling my family how much I'd lost.
'I'd never experienced such disastrous financial trouble like this in the past. I'd paid off my mortgage and had a nice house, a family home. I had no clue that you could so easily lose all that almost overnight.'
Dame Clare Moriarty, chief executive of Citizens Advice, said: 'Anyone can fall victim to a scam and we know scammers aren't only targeting those looking to invest money, but also those simply going about their day-to-day lives.
'It's particularly worrying to see the impact on people's finances afterwards, especially if they have to borrow to get by.
'It's important for us all to be on our guard - if you're not sure about something, take your time and get advice.'
Lord Michael Bichard, chairman of National Trading Standards, said: 'With the cost of living still high, criminals are preying on people looking for ways to strengthen their finances or reduce their debt. Not only is their money stolen, but the effects on their health and wellbeing can be devastating.
'People should be wary of anyone offering financial advice out of the blue, particularly on social media.
'We urge anyone who has been a victim of a scam to report the crime. Underreporting of scams is a major problem and we need people to come forward so we can stop these criminals in their tracks.'
John Herriman, chief executive of the Chartered Trading Standards Institute (CTSI), said: 'CTSI is very concerned to see the number of people that are targeted every year by financial scams, whether these are fake debt, pension advice, or parking scams.
'The vast number of people affected by these scams shows there is an urgent need for more consumer awareness in this area. The hope is that this campaign will remove the stigma associated with being the victim of a scam and that those affected can be empowered to come forward and help to bring these criminals to task.'
Jane Parsons, a Citizens Advice consumer expert, said that key warning signs of scams include something seeming too good to be true, when you are put under pressure to transfer money quickly, being asked to pay in an unusual way such as using a voucher or transfer service, being asked for personal information such as passwords or signs the person or organisation is not genuine - such as a strange email address.
