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Sending physical mail can sometimes feel like a relic of the past. We usually just text or Whatsapp each other. But there are occasions when sending a large letter or package is necessary, whether it’s to a mate or just life admin. One of the most common questions that arise during this process is: “How many stamps do I need for a large letter?” This seemingly simple question can actually be quite complex, depending on various factors such as the letter’s weight, size, and destination.

In our posting guide, we cover all this info so you know exactly what a large letter is (compared to a normal letter or parcel) and how to actually go about sending one. So you can send off all those important docs, those personalised handwritten letters or whatever you want to send that can’t be done over the phone. From weighing your letter to understanding the different types of stamps and postal rates, and even tracking your large letter’s journey, we’ve got you covered.

How big is a large letter?

how big is a large letter

So first of all, it’s worth noting that Royal Mail splits post into the following categories: small parcel, medium parcel, large parcel, tube, letter, and large letter. A letter is anything up to 24×16.5×0.5 cm (L x W x D), and a large letter is 35x25x2.5cm (or 353mm x 250mm x 25mm), anything bigger than that will come under a parcel category.

Here are the sizes for different kinds of letters:

  • Letter (240mm x 165mm x 5mm)
  • Large Letter (353mm x 250mm x 25mm)
  • Small Parcel (450mm x 350mm x 160mm)
  • Medium Parcel (610 mm x 460mm x 460mm)
  • Large Parcel (1500mm – combined length, width and depth less than 3m or 3000mm).

How many stamps do I need?

When it comes to how many stamps you need, it depends on the weight. The easiest and probably cheapest way to figure this out is to take your item to the post office. There, they can weigh it and stamp it for you, and charge you correctly.

Royal Mail - how many stamps for a large letter
Source: Royal Mail


Alternatively, you can buy stamps singularly or in books. If you’re doing it this way, says you will need:

  • 2 first class or second class stamps for a letter weighing 0 – 100 grams
  • 3 first class or 2 second class stamps for a letter 101-250 grams
  • 3 first or second class stamps for a letter 251 – 500 grams,
  • 4 first or second class stamps for anything between 500 and 750 grams.

If it weighs more than 750 grams, you will need to pay rates for a parcel.

What do I say at the post office?

What do I say at the post office?

If you’ve never had to post something via the post office before, it can be daunting. All the staff in their little booth, scales everywhere, envelopes surrounding you… but not to worry, we have your back.

First of all, before you go up to the counter, make sure you have packaged the parcel or letter, and that the full address is written on the front. You may also want to include your address on the back under ‘SENDER:’. This ensures that if there are any issues with delivering your parcel, it will be returned to you.

Secondly, you want to join the queue and head over when called. Once at the till, just say simply ‘I’d like to post this’. They’ll ask you to place your item on the scale, and then pass it through to them. They’ll take it from there. You’ll be asked first or second class, and then you will see them stamp it, type out the address, and then put it out the back. They’ll charge you, and if provide you with your receipts.

How do I track my parcel/letter?

On the receipt, you will have a 9 to 27 character long code. If you download the Royal Mail app or go to this page, you can track your parcel all the way to it’s receiver.

Royal Mail have their own array of tips and tricks online – check them out!

Other considerations when posting letters 

how many stamps for a large letter - other considerations

When it comes to mailing large letters, especially in special circumstances, there are several key factors to consider:

International mailing

Sending letters across borders is not as straightforward as domestic mailing. Different countries have varying postal regulations, rates, and delivery times. It’s crucial to check the specific international rates and any restrictions that might apply to your destination country. For instance, some countries have strict guidelines on what can be sent through the mail, which might affect your ability to send certain items.

Tracking and insurance

In certain scenarios, you might want the added security of tracking your letter or insuring its contents. This is particularly relevant for important documents or valuable items. Most postal services offer tracking and insurance at an additional cost. Sometimes, these services are bundled together for convenience. It’s a small price to pay for peace of mind, especially when sending something of significant value or importance.

Customs declarations

For international mail, customs declarations are a common requirement. This involves filling out a form that details the contents and value of what you’re sending. This step is crucial for customs clearance and ensures that your letter adheres to international mailing regulations. Neglecting this step can result in delays or even the return of your mail.

Handling oversized or unusually shaped large letters

If your letter exceeds the standard dimensions (often defined by length, width, and thickness), it may be classified as a parcel. This reclassification usually means a different rate structure and possibly different mailing requirements. It’s essential to check with your postal service to understand how oversized items are handled and priced.

Letters that don’t conform to the standard rectangular shape, such as square or circular envelopes, can be more challenging to process through automated mail equipment. As a result, these items often incur additional charges. It’s always a good idea to check if there are any extra fees for non-standard shapes to avoid any surprises.

Where to purchase stamps for large letters

Where to purchase stamps and send large letters

You can buy stamps for large letters from different places. These include:

Post offices: The most traditional and reliable place to purchase stamps is at a post office. Here, you can find a wide range of stamp denominations and types to suit various mailing needs. Post offices also provide valuable assistance and advice, ensuring you buy the correct postage for your letter.

Online: Many postal services have embraced digital convenience, allowing customers to purchase stamps online. This option often includes the ability to print postage from the comfort of your home or office, which is particularly useful for bulk mailings or business purposes.

Retail stores: Stamps are widely available at various retail outlets, including supermarkets, convenience stores, and stationery shops. This option is handy for those who need to buy stamps while running other errands.

Where can you post large letters?

where to post large letters - mailboxes

Post Office: For large or special letters, especially those that are oversized or require additional services like tracking or insurance, visiting a post office is recommended. The staff can confirm if your postage is correct and assist with any special mailing requirements.

Mailboxes: If your letter has the correct and sufficient postage, dropping it in a public mailbox is a convenient option. These mailboxes are typically collected at regular intervals and are a quick way to send off your mail.

Scheduled Pick-Up: For those with busy schedules or mobility issues, some postal services offer a home pick-up service for a fee. This service can be particularly useful for sending large quantities of mail or bulky items that are difficult to transport.

Yes, you can use two stamps for a large letter, provided the combined value of the stamps covers the current postage rate for a large letter. It's important to ensure that the total value of the stamps equals or exceeds the required postage. If you're unsure about the total postage needed, it's advisable to check with your local Post Office or refer to the Royal Mail's website for the latest rates.

A single first-class stamp is typically not sufficient for a large letter. The postage for a large letter in the UK is higher than that for a standard letter. As of my last update, a standard first-class stamp covers only the cost of a standard letter up to a certain weight. For a large letter, you will need either a large letter stamp or multiple standard stamps that add up to the equivalent postage rate. It's always best to verify the current rates on the Royal Mail's website or at a Post Office.

The cost of a first-class stamp for a large letter in the UK varies depending on the weight of the letter. As of my last update, the price for a large letter starts at a certain amount for items up to 100g and increases for items up to 250g, 500g, and 750g. However, postal rates are subject to change, so I recommend checking the most current pricing on the Royal Mail's website or at your local Post Office for the latest information.