The Department for Trade and Industry issued an alert after looking at the most common scams detected in the past year.
They include "get rich quick" property schemes and bogus claims about the rental value of buy-to-let properties in poor condition.
Among other scams identified are advertising individual plots of agricultural land with no development potential and trying to charge companies for office supplies they had not ordered.
Consumer minister Gerry Sutcliffe said, "It is a sad fact that the scams and rip-off money-making schemes continue to resurface in a number of different guises, usually taking advantage of people's good nature or desire to make a bit of money."
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