Skip to main content

Sending tips and size and weight guidelines 

What are you sending?

An Post divides mail into four categories to determine the cost of its delivery:

Once your item exceeds the size or weight limit of any category, it automatically moves to the next category of post.

Get more information on:

Letters and postcards

The letter/postcard rate of postage applies to items no larger in size than C5, the size of an envelope containing a folded A4 sheet of paper. Most letters, postcards, bills, statements and greeting cards fall into this category.

To qualify for this rate of postage, items must weigh no more than 100g and meet the following size requirements:

  • Minimum 14cm long, 9cm wide, 0.018cm deep (with a tolerance of 0.2cm)
  • Maximum 23.5cm long, 16.2cm wide, 0.5cm deep

Small items must be inserted into an envelope of at least the minimum dimensions to meet regulations or they may be charged at the parcel rate.

Large envelopes

The large envelope rate of postage applies to flat items, such as an A4 sheet of standard paper. Documents, brochures, magazines, CDs and DVDs fall into this category.

To qualify for this rate of postage, items must weigh no more than 500g and meet the following size requirements:

  • Minimum 14cm long, 9cm wide, 0.018cm deep (with a tolerance of 0.2cm)
  • Maximum 40cm long, 30cm wide; 2.5cm deep


To qualify for the packet rate of postage, items must weigh no more than 2kg and meet the following An Post packet size requirements:

  • Minimum 10cm long x 7cm high x 2.5cm deep
  • Maximum a combined length, height and depth of 90cm (no individual dimension can exceed 60cm, with a tolerance of 0.2cm)
  • In tube form, the length plus twice the diameter must be less than 104cm with no one dimension exceeding 90cm (with a tolerance of 0.2cm)

Gifts, books, product samples, posters and prints in cylindrical tubes will usually fall into this category.


The parcel rate of postage applies to items weighing up to 20kg and with the following maximum dimensions:

  • Length 1.5 metres
  • Length + girth 3 metres (where the girth equals 2 x [depth + width])

Large boxed items such as electrical goods, components and irregularly-shaped and cylindrically-shaped items such as large posters fall into this category.

Dimensional weight

Large but light parcels, such as a box of pillows, may be charged according to their dimensional weight to reflect the full cost of their transport.

To calculate the dimensional weight, multiply the length in centimetres by the width by the depth and divide by 6,000. For example, the dimensional weight of a 10kg item, which is 62cm long, 49cm wide and 39cm deep is (62x49x39)/6000 = 19.75. This is rounded up to 20, giving a dimensional weight of 20kg.

Ten tips for sending your post and parcels

You've put a lot of thought and care into what you are sending so follow these ten tips to make sure your item is delivered on time:

  1. Choose the service that best matches your needs, be they cost, speed or security
  2. Ensure the destination address on your item is current, correct and complete
  3. If posting to Dublin, include the postal district number, for example Dublin 3, and add the Eircode
  4. Put a return address in the top left hand corner so undelivered mail can be sent back
  5. Attach the correct postage for the size and weight of your item and its destination
  6. Seal the envelope or secure the parcel to ensure deliveries arrive intact and on time
  7. Attach the correct labels, such as Airmail or customs labels to items going abroad
  8. Check your packaging to make sure it’s strong enough and mark fragile items
  9. Do not send prohibited items such as liquids outside of Ireland
  10. Keep your receipt, with the number that allows you to trace trackable items, until you know they have been safely delivered

Prepare your parcel for postage

To make sure your parcel arrives safe and sound, follow these general tips on packing and wrapping:

  • Check that the address is complete, correct and legible and includes a full post or zip code where applicable
  • Fill out and attach the appropriate customs forms for parcels going overseas. These are available from your local post office
  • An Aviation Security Declaration must be attached to any parcel or packet sent within the EU, excluding Northern Ireland
  • Mark your parcels with appropriate labels such as Fragile, Do Not Bend or Heavy for parcels that weigh more than 5kg
  • Attach the parcel service label to the centre on top as parcels are machine processed on their largest, most stable side, usually the base
  • Use plenty of protective packing material, such as bubble wrap or polystyrene chips, to protect your items and fill all spaces so the contents of the package don’t move
  • Use strong tape along all openings and edges and put keys, coins or loose materials in a jiffy or padded envelope

How to speed up your deliveries

Did you know that the colour, size and the weight of your envelope can dictate how soon your post gets to its destination?

An Post uses Optical Character Recognition (OCR) mail processing equipment which can sort through 40,000 pieces of mail per hour. To speed up your delivery and get the most out of OCR follow these guidelines:

  • Always use block capitals when hand writing addresses and avoid colour, italics and underlining if typing it
  • Do not include punctuation marks in the address
  • Choose light-coloured envelopes as those with dark backgrounds such as red, blue or green are unreadable
  • Items to be sent outside Ireland should be marked with an Air Mail label, which you can pick up at your local post office and attach to the left of the postage area
  • Do not use staples, metal or plastic clips on the envelope