Energy firms in the UK will be writing to customers over the next few days to warn them of energy bill rises in April.
According to Citizens Advice, energy suppliers must provide their customers with "reasonable notice" of price rises or changes which will leave them worse off.
With the Government's current plan of upping its Energy Price Guarantee (EPG) to £3,000 from £2,500 next month, customers will need to be told about the changes as soon as possible.
