It is important to pay the correct postage when sending your mail

Australia Post offers several ways for you to post your mail, including through red street posting boxes conveniently located throughout Australia.

It is the responsibility of the sender to apply the correct postage for their items before posting them.

Please read our postage guide to learn how your item’s length, width, thickness, and weight affect the total postage cost.

Where an item’s dimensions, weight or thickness are outside what is allowable for a letter, it must be charged as a parcel.

Will my mail still be delivered if I incorrectly calculate my postage?

Australia Post can carry an item with insufficient postage and then issue an Underpaid Mail invoice to the sender to claim the amount of the deficient postage plus an underpaid item adminstration fee for each item that has deficient postage. 

We may also decide to take other actions depending on the circumstances, such as withholding the item for delivery until the deficient postage is paid or seeking payment from the addressee when a sender is not identified.

Where we take such actions, we will communicate this directly to the sender, or where the sender cannot be identified, to the addressee.

You can read more about recovery of postage on underpaid items under Section 4.7 of the Australia Post General Terms and Conditions (PDF 1.64MB) and find out about the Underpaid Item administration fee in the Post charges guide (PDF 813kB).

Counterfeit products and consistent lodgement of underpaid items

When Australia Post detects mail lodged with counterfeit stamps or prepaid satchels, it is classified as Underpaid Mail, within the postal system.

In these instances (or if we determine that the sender consistently lodges underpaid Items), we may:

(a) refuse to carry the item; or 
(b) hold the item and notify either the sender or the addressee that proper postage plus an underpaid Item administrative fee (as set out in the Post Charges Guide) 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 per the Australia Post General Terms and Conditions.

While we acknowledge that this may have been unintentional, please note that the use of stamps or prepaid satchels not issued or authorised by Australia Post to send items is a breach of our Terms and Conditions. It may also be an offence under the Crimes Act 1914.

For your future needs, we recommend purchasing Australia Post stamps and prepaid satchels only from Australia Post outlets or our official website.

FAQs