Paying the correct postage

When sending parcels or letters through our network, it’s important you apply the correct postage before posting them.

Read our size and weight guidelines to check how length, width, thickness and weight affect the total postage cost.

If your letter exceeds our maximum size and weight limits, it will be considered a parcel. If you need help weighing your letter, visit your nearest Post Office.

Delivering mail with incorrect postage

We may still deliver an item even if it doesn’t have enough postage. However, we may issue an Underpaid Mail invoice to the sender to cover the balance of the postage, as well as an administration fee.

In some cases, we may:

  • hold the item until the correct postage is paid, or
  • seek payment from the receiver if we can’t identify the sender.

For more details:

Sending with counterfeit products

When a parcel or letter is sent with counterfeit stamps or prepaid satchels, we classify it as Underpaid Mail.

When detected, or if we determine that a sender consistently posts items with underpaid postage, we may:

(a) refuse to carry the item; or

(b) hold the item and notify either the sender or the receiver that proper postage plus an administrative fee (as set out in the Post Charges Guide (PDF 813kB) is payable before we deliver the item. If these costs are not paid within seven days, we may deal with the item under clause 4.6(d) as outlined in the Australia Post General Terms and Conditions (PDF 1.64MB).

Using stamps or prepaid satchels not issued or authorised by Australia Post, even unintentionally, is a breach of our terms and conditions. It may also be an offence under the Crimes Act 1914.

We recommend purchasing Australia Post stamps and prepaid satchels only from Australia Post outlets or our Online Shop.

Frequently asked questions