New prices set to come into effect later this year will see the price of a single first-class stamp jump to 95p.
The rise marks an increase of 10p, with second class stamps also set to increase by 2p from April 4.
It comes as Royal Mail faces the dual problem of a long-term decline in letter usage and rising inflation.
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The volume of letters sent has fallen by more than 60 per cent since their peak in 2004/5 and by around 20 per cent since the start of the coronavirus pandemic.
As reported by Wales Online, Nick Landon, chief commercial officer at Royal Mail said: “We understand that many companies and households are finding it hard in the current economic environment, and we will always keep our prices as affordable as possible.
"Whilst the number of letters our postmen and women deliver has declined from around 20 billion a year to around seven billion since 2004/5, the number of addresses they have to deliver to has grown by around 3.5 million in the same period.
“We need to carefully balance our pricing against declining letter volumes and increasing costs of delivering to a growing number of addresses six days a week.
"As customer needs change and we see a greater shift from letters to parcels, it is vital that the universal service adapts to stay relevant and sustainable.
“These price changes are necessary to ensure we can continue to maintain and invest in the one-price-goes-anywhere universal service for future generations.”
"It is the latest price rise to affect families as the cost of living crisis continues. The price of petrol at the pump has risen to record highs and households are finding out about huge increases to gas and electricity bills."
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