Martin Lewis' Money Saving Expert team has a warning about an upcoming steep increase in the cost of Royal Mail's first-class stamps.

Starting from Monday, October 7, just 30 days from now, the price of a standard first-class stamp will rise by 30p, from £1.35 to £1.65—a significant 22% increase.

The hike comes as Royal Mail responds to mounting cost pressures, citing its legal obligation to deliver letters to every UK address six days a week, known as the "universal service obligation."

Nick Landon, the company’s chief commercial officer, said: "We always consider price increases very carefully."

He added: “However, when letter volumes have declined by two-thirds since their peak, the cost of delivering each letter inevitably increases."

The MSE team, led by consumer expert Martin Lewis, is urging customers to stock up on stamps before the price change.

Stamps purchased now will remain valid for use even after the new prices come into effect.

This could be an opportunity to save, as first-class standard stamps will see a 30p rise, and first-class large letters will increase by 50p, from £2.10 to £2.60—a 24% hike.

However, the price of second-class stamps remains unchanged.

A second-class standard letter will continue to cost 85p, and a large second-class letter will remain priced at £1.55.

These increases are part of an ongoing trend, with the cost of first-class stamps already rising by 14% in October 2023 and by an additional 8% in April 2024.

The latest price jump is likely to hit consumers hard, particularly given the rising cost of living in the UK.

The warning from MSE came as the Royal Mail made the announcement on Friday.