Australia Post

Australia Post is a premium shipping method that allows your store to fetch rates from Australia Post’s API and calculate shipping for orders.


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  • Your store must use Australian Dollars (AUD) as its currency
  • Base location of your store is Australia


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  1. Download the .zip file from your WooCommerce account.
  2. Go to: WordPress Admin > Plugins > Add New to upload the file you downloaded with Choose File.
  3. Activate the extension.

More information at: Installing and Managing Plugins.

API Key and Debug

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You can set this under WooCommerce > Settings > Shipping > Australia Post

API access details are on the Australia Post website. Obtain your own key, or use ours.

  1. API Key – Get this from Australia Post or leave blank to use our API Key.
  2. Debug Mode – Enable/disable debug mode to show debugging information on your cart/checkout.

Setup and Configuration

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This shipping method has to be added to a Shipping zone. If you haven’t configured your Shipping zones yet, please check our Setting up Shipping Zones guide before proceeding.
  1. Go to WooCommerce > Settings > Shipping > Shipping zones.

2. Click the Edit button on the shipping zone where you want to offer this method.

3. Inside the shipping zone, click the Add shipping method button.

4. Then, select the shipping method and click the Continue button.

  • Click the Edit button on the right side of the Shipping methods table to configure the settings:
    • Method Title – Name the shipping method. This is visible to customers.
    • Origin Postcode – Should be set to the postcode from where you ship, and is sent to the Australia Post API.
    • Method Availability –  Allows you to narrow down the countries that get quotes. Leave set to All Countries to make available to all customers.
    • Rates and Service Settings – Control the services and rates you offer customers.
      1. Parcel Packing Method – See below.
      2. Offer Rates – Choose to return all rates (user will get the choice) or the cheapest rate.
      3. Services – Here you can enable/disable, re-order, rename and configure Australia Post shipping rates.
  • Save.

Parcel Packing Methods

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There are three packing methods with Australia Post; each affects the parcels you send to the API.

Pack items individually (Default)

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Each item in your cart (non-virtual) is sent to the Australia Post API. Quotes for all items are combined for the final cost.

Weight of all items

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The combined weight of all items in the cart is used to calculate the cost. If the package becomes too heavy, it is split. Using this method, a Maximum weight field appears and must be filled out.

Pack into boxes with weights and dimension (Recommended)

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Items are packed into pre-defined boxes and sent to the API. We recommend this option. See Box-Packing below for more information on this.


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The box packer included with this shipping method lets you group items into packages of which you define the height, width, length, weight and max weight. The packing is mainly volume based, but does also consider item sizes too.

The box packer is volume based. This will in most cases provide good results, but will never be as accurate as a real person packing a box (see BIN Packing Problem). Therefore it is important you understand that packing results are as accurate as they can be and any anomalies should be accepted.

Setting up box sizes

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Within the settings, look for the boxes setting. Click ‘add box’ to set up the boxes dimensions:

Box settings

Outer dimensions are used for parcel dimensions and are passed to the API.

Inner dimensions are used for packing, and items will be fit within these.

Weight of box is the weight of the actual box, and will be added to the weight of the contents.

Max weight is the maximum weight your box can hold. This includes contents weight and box weight.

Type: This checkbox determines whether your package is a box, envelope, packet, or tube.

How the calculation works

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The packer does the following:

  1. Finds boxes which fit the items being packed (uses H x W x D).
  2. Packs all fitting items into boxes (using volume).
  3. The largest box which fits 100% of items is used *or* use the highest % packed box, and then pass unpacked items back (and repeat the process)
  4. Unpackable items are packed alone, using the item dimensions.
  5. All packed boxes are returned.
The Australia Post API requires that your non-virtual products have weights and dimensions set. More at: Adding Dimensions and Weights to Products for Shipping.

Satchel Rates

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Satchel Rates are flat rates that you can use, instead of defining box sizes. If Satchel Rates are enabled on your site, then items are calculated based on one of three satchels available:

  • 500g satchels are 335mm x 220mm ( W x H ) and are suitable for shipping CDs, iPods, mobile phones.
  • 1kg satchels are 385 x 265mm ( W x H ).
  • 3kg satchels are 405mm x 310mm ( W x H ) and are suitable for Fashion, books, digital cameras, toys.
  • 5kg satchels are 510 x 435mm ( W x H ).

There are three options regarding the Satchel Rates dropdown:

  • Enable Satchel Rates – Uses the above satchels to calculate shipping, which ignores your custom boxes.
  • Prioritize Satchel Rates – Uses Satchel Rates when applicable, but if your item does not meet criteria or fit in the satchel box, it will use a custom box size.
  • Disable Satchel Rates – Ignores Satchel Rates and uses your own boxes.

If you don’t intend to use the pre-defined satchels and want to use your own box sizes for the calculator, you need to select the option Disable Satchel Rates.


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In the Services section of the menu, you can choose which Australia Post services you want your customers to receive.

Australia Post Service Options

There are a few fields to note:

  • Extra Cover is an optional selection that will increase the price of your shipping by adding additional insurance during transfer.
  • Signature / Registered is another optional selection to cover tracking and (if purchased) signature at delivery.
  • The Adjustment fields increase shipping by a flat amount or percent. A blank field leaves rates untouched.
    • i.e. Your shipping is $10 with $5 in Adjustment ($) – the customer will be charged $15 for shipping.
    • i.e. Your shipping is $10 with %15 in Adjustment (%) – the customer will be charged $11.50 for shipping.

Customer Usage

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Customers will get quotes (after inputting their address) from two places:

  • Cart page – by using the shipping calculator
  • Checkout page – by filling in the shipping and billing forms
Rates can be selected by customers as normal.


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No rates returned/no rates available

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  • Ensure your API credentials are correct.
  • Enable development mode, or turn on WP_DEBUG to see debugging information on the cart page. This will often reveal the problem.
  • Check your products have sizes and weights set – without this the calculation cannot be performed.
  • Check your store’s base country is Australia and that your using Australian Dollars (from WooCommerce > Settings > General).

Error message in cart: Fatal error: Cannot use object of type WP_Error as array in ../woocommerce-shipping-australia-post/classes/class-wc-shipping-australia-post.php on line 1086

You can see this error message if your server can not use the wp_remote_get() function. This is something you can verify in the Status Report:


In this case, we recommend you to contact your hosting company so that they update your server.

How do I adjust tax rate?

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Note: We are unable to provide support for customizations under our Support Policy. If you are unfamiliar with code/templates and resolving potential conflicts, select a WooExpert or Developer  for assistance.

If you need to adjust tax rate, you can add the following snippet to the file called “functions.php” within your theme folder:

add_filter( 'woocommerce_shipping_australia_post_tax_rate' , 'woocommerce_shipping_australia_post_custom_tax_rate' );
* Adjust tax rate
* @access public
* @since 1.0
* @return void
function woocommerce_shipping_australia_post_custom_tax_rate() {
return '0.09090909';

Frequently Asked Questions

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Does this support discounted/negotiated rates from Australia Post Business?

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No. And there are no plans at this time to add it in the future.

How do I make it return Australia Post Letter Rates?

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To get Australia Post to return letter rates, you will have to configure custom boxes in the extension using the Pack into boxes with weights and dimensions (Recommended) method.

Once you have chosen this method, please be sure to enter the box sizes you require (please ensure that these box sizes are same as the letter-box sizes mentioned in the Australia Post website – otherwise the extension will not calculate letter rates), and please select Envelope from the drop down list:

By doing this, the Australia Post extension will fetch letter rates using the API, and fetch accurate letter rates for your customers.

How do I make it return Australia Post Satchel Rates?

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Satchel rates will be returned if the item (or the outer dimensions of your boxes, if you are using box packing) fit inside the satchel dimensions.

  • 500g satchels are 335mm x 220mm ( W x H ) and are suitable for shipping CDs, iPods, mobile phones.
  • 1kg satchels are 385 x 265mm ( W x H ).
  • 3kg satchels are 405mm x 310mm ( W x H ) and are suitable for Fashion, books, digital cameras, toys.
  • 5kg satchels are 510 x 435mm ( W x H ).

When a service is made up of several types of rate, including satchel, e.g. Regular Post, Satchel rates will only be used if they are the cheapest.

If you are using box packing, choose a box L x W x H outer size which would fit inside a satchel. The length you use is up to you – usually this will be determined by the products being shipped.

Questions and Feedback

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Have a question before you buy? Please fill out this pre-sales form.

Already purchased and need some assistance? Get in touch with a Happiness Engineer via the Help Desk.