The Royal Mail is increasing the cost of posting a standard letter both First Class and Second Class by up to 3p.
The new changes, which will be introduced next month, mean the prices of sending letters First Class has doubled in the last decade.
Which? explains the stamp prices change and looks at the increase in charges for using Royal Mail postage since 2015.
The price of a First Class stamp, for a standard letter weighing up to 100g, will increase by 3p from 67p to 70p.
The price of a Second Class stamp for a standard letter will rise as well by 3p from 58p to 61p.
These changes will take effect from March 25.
Following the announcement on Friday (February 22) it emerged the Second Class price rise breached Ofcom's cap of 60p which was in place until April 1.
Royal Mail has apologised and pledged to donate the anticipated extra revenue of £60,000 to the charity Action for Children.
Despite the price rises, the Royal Mail claimed its prices are 'among the best in Europe'.
The company said in a statement: 'Royal Mail researchshows that the European average for 1Class letters (0-100g) is 99p.
'The UK 1Class stamp price comes in at below this price.
'The European average for 2Class letters (0-100g) is 77p, and the UK 2Class stamp price remains below this.
'Royal Mail understands that many companies and households are finding it hard in the current economic environment.
'As a result, we have considered any pricing changes very carefully and in doing so have sought to minimise any impact on our customers.'
Since 2015 when the cost of a First Class stamp was 63p and a Second Class stamp 54p, the price of posting letters has increased every year.
The 2019 increase of 3p was the largest rise in stamp prices in the past five years.
Postage costs have more than doubled in the past decade.
The cost of a First Class stamp for a standard letter weighing up to 100g was 34p in 2007.
Royal Mail is still generally considered the cheapest option for sending cards, letters and small parcels under 1kg.
An alternative would be to bulk buy stamps before the changes are introduced in March.
Another website www.postofficeshop.co.uk offers a pack of 12 First Class stamps for £8.04, which is equal to the current price of a single First Class stamp at 67p.
A former English teacher Rowland Hill is credited with inventing the postage stamp, a pre-paid system where everyone would be charged the same rate and which launched in Britain in 1840 with the Penny Black.
It revolutionised the postal system as more than 350 million paid-for letters were sent in 1850 compared to 76 million in 1939.
Before the stamps were introduced, charges were based on how many sheets you used and as the recipient paid, they could refuse to receive a letter.