How strict are the royal mail with letter dimensions

Royal Mail, the postal service in the United Kingdom, has specific guidelines for letter dimensions to ensure efficient sorting and delivery. While they are generally flexible, there are some strict guidelines to follow to avoid issues with delivery or additional fees. Here are the key dimensions to consider:

Standard Letter (up to 100g)

• Maximum dimensions: 240 mm (9.4 in) long, 165 mm (6.5 in) wide, and 5 mm (0.2 in) thick
• Maximum weight: 100g (3.5 oz)

Large Letter (up to 750g)

• Maximum dimensions: 353 mm (13.9 in) long, 250 mm (9.8 in) wide, and 25 mm (1 in) thick
• Maximum weight: 750g (26.4 oz)

Large Letter (over 750g)

• Maximum dimensions: 353 mm (13.9 in) long, 250 mm (9.8 in) wide, and 25 mm (1 in) thick
• Maximum weight: No limit, but may incur additional fees

Special Restrictions

• Envelopes with a gusset (a fold or pocket) must not exceed 100 mm (3.9 in) in depth.
• Envelopes with a rigid insert (e.g., a CD or DVD) must not exceed 10 mm (0.4 in) in thickness.
• Envelopes with a non-standard shape (e.g., a square or irregular shape) may be subject to additional fees or special handling.

Additional Tips

• Make sure to leave a 5 mm (0.2 in) gap between the top of the envelope and the address label to ensure easy sorting.
• Use a sturdy envelope that can withstand handling and transportation.
• Avoid using envelopes with excessive weight or bulk, as this may cause issues during sorting and delivery.

If your letter exceeds these dimensions or has unusual features, you may need to use a special delivery service, such as Royal Mail's Large Letter or Parcel services, which may incur additional fees. It's always a good idea to check with Royal Mail or consult their website for the most up-to-date information on letter dimensions and requirements.