Free Dpd Next Day Delivery on orders £100 or above (UK Mainland only, Cut off time 3pm)

Royal Mail Large Letter Cardboard Boxes - 325x225x20mm - Pack of 50

Royal Mail Large Letter Cardboard Boxes - 325x225x20mm - Pack of 50

Royal Mail Large Letter Cardboard Boxes - 325x225x20mm - Pack of 50

Regular price £16.00
Next Day Delivery
Same Day Dispatch

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Royal Mail Large Letter Cardboard Boxes

Our Royal Mail postal boxes are specifically designed to fit through standard letterboxes, making them perfect for the Royal Mail's Large Letter service. These boxes are crafted from single-wall corrugated paper, which offers superior protection compared to plastic mailing bags, ensuring that important documents and similar items are securely shielded during transit. Utilising the Large Letter option is one of Royal Mail's most cost-effective courier services, helping you keep shipping costs down. Additionally, our postal boxes are not only biodegradable but also compostable, aligning with eco-friendly practices by helping to reduce waste and promote sustainability in packaging.

Length 325mm
Width 225mm
Height 20mm

Suitable for Royal Mail

When selecting boxes and packaging, it's crucial to choose options that meet the specific requirements of the service you're using. Royal Mail has strict guidelines on what qualifies as a Large Letter, so using the right size boxes is essential to avoid any unexpected charges for oversized items. Our cardboard boxes are designed to adhere to these dimensions, ensuring you won't face additional fees. They are also affordable, making them a cost-effective choice for your mailing needs. Plus, they come in plain brown cardboard, which can be easily customised with stickers or stamps to add your branding, providing a professional look while keeping costs low.

Biodegradable & Compostable Provides Maximum Protection Lightweight and Durable

Affordable Packaging Supplies

At Mr Bags, we offer a range of trusted packaging supplies with a variety of affordable options to suit any parcel size. Our selection includes everything from large cardboard boxes to cardboard storage boxes, catering to all your storage and shipping needs. In addition to our extensive range of boxes, we also provide packaging tapes, honeycomb envelopes, plastic options, and many other packaging essentials. Whether you're sending a small parcel or need robust solutions for larger items, Mr Bags has the packaging supplies to ensure your items are protected and secure.

Reliable Royal Mail Boxes

Our Large Letter Royal Mail boxes are made from single-wall corrugated paper, a material that combines lightness with durability, ensuring your parcels are both easy to handle and well-protected. These boxes are designed to withstand heavy handling, keeping your items secure

Eco-Smart Postal Boxes

Sustainable packaging is essential, and our Royal Mail postal boxes offer eco-friendly benefits over plastic postage bags. Made from materials that are 100% recyclable, biodegradable, and compostable, these boxes help reduce environmental impact while ensuring your parcels are securely delivered

Convenient Postage Boxes

Our large letter cardboard boxes are flat-packed, reducing the storage space required in your home or office. These boxes are quick and easy to assemble, increasing efficiency during busy periods. Pairing these boxes with brown parcel tape ensures that the contents remain fully concealed

Versatile Shipping Boxes

Our large letter-sized shipping boxes are versatile, accommodating a wide range of items such as books, electronics, textiles, and other goods. These cardboard boxes are not limited to Royal Mail services; if the dimensions match, they are perfect for numerous other uses

100% Recycable
Corrugated Board
Durable Design
Single Wall

Royal Mail 24 Tracked

Dispatched same day if ordered before 5 pm Monday to Friday. Please allow up to 1-2 days for delivery.


DPD Next Day

Dispatched same day if ordered before 3 pm Monday to Thursday. Not available to Scottish Highlands & Islands.


Free on orders over £100