Stamp prices have officially risen in price, with the cost of a standard first class letter 70p from today.
The changes, as announced in February, now mean you'll have to fork out 61p for a second class stamp and 9p more to have it delivered even quicker.
In line with the rise, first class stamps increased by 3p to 70p and second class stamps by 3p to 61p.
Last month, the Royal Mail said the pressure on households was taken into account when setting the new rates - and said the costs were still competitive.
"Stamp prices are among the best value in Europe when compared to other postal operators," a statement said.
New rules also kick for those who are redirecting post from today.
As of Monday, pricing will be based on the number of applicants rather than on a per-surname basis to be more reflective of modern society.
The company has faced criticism in the past for assuming people who lived at the same address shared a surname - with many campaigners pointing out that this meant people who did not take their spouses name, or were unmarried, paid more.
The changes kick in just months after Royal Mail was forced to make a pub apology over the cost of rising stamps.
In March 2012, regulator Ofcom imposed a price cap on second class standard letters. The cap was set for 2012/13, to increase by no more than inflation for seven years.
The regulator's cap of 60p was supposed to be in place until 1 April 2019.
Royal Mail has subsequently said it will donate the extra revenue, expected to be £60,000, to charity Action for Children.
