First Class Mail Letter Size

First Class Mail Letter Size. Greetings cards, personal letters and postcards. To be eligible for mailing at the price for letters, a piece must be:

Max 750g | max l 35.3cm. Royal mail 1st class for personal customers. Format and max measurements max weight 1st class 2nd class;

Weight 1st class 2nd class;

Unlike postcards, they receive a price break when sent at marketing mail rates. The maximum size is 250 mm x 353 mm and and a maximum weight of 750g so a c4 envelope is a good choice. Additional size restrictions apply depending on the type of mailpiece you're sending. Cost for sending a large letter.