A Comprehensive Guide to Australia Post Letter Costs

Whether you’re running a small business or just sending more than the average amount of letters, it’s worth keeping up to date on the current Australia Post letter costs and postage rates for 2025. The difference between one letter option and another might not seem like much at the time, but the more frequently you send letters, the faster postal service costs add up.

As Australia’s national postal service, Australia Post provides access to the biggest postage network across Australia, with post offices located everywhere, from major cities to rural towns. It’s easy to see why many individuals and businesses alike rely on Australia Post for their postage needs.

However, getting your letters where they need to be on time while staying on budget is a little more complicated than simply asking, ‘How much to post a letter in Australia?’

Australia Post updates its postage rates regularly, so knowing the latest stamp price can help you plan your mailing costs more accurately. They also offers a range of service options based on speed, size and budget. But which ones should you be choosing? Your letter is urgent, but should you go for priority or express? Should you use a prepaid envelope or stick with stamps? And just how much is a postage stamp in Australia? With so many options available, it’s easy to get overwhelmed.

Fortunately, Interparcel is here to help.

This guide covers the cost to mail a letter in Australia, depending on the different services provided by Australia Post, and will help you make the most appropriate choice. While Interparcel doesn’t offer letter-only postage, many of our customers still ask about Australia Post letter prices and delivery times, so this simple guide will help you to understand how they work, including what to do when your item no longer qualifies as a letter.

The Factors Influencing Your Postage Rates

Australia Post offers a range of different postage services. The size and weight of your letter or parcel will determine the postage amount you need to pay.

1. Australia Post’s Letter Service Types

Regular

The regular letter service includes small and large letters and usually takes 3-7 business days to arrive at their location, depending on where it is.

Priority

The priority letter service also includes small and large letters and generally takes 2-4 business days to arrive at their location.

Express

Express, Australia Post’s fastest letter-sending service, generally takes 1-3+ business days. Express Post's next business day delivery guarantee covers most capital cities and some major centres across Australia. Express service also automatically includes tracking and up to $100 compensation for loss or damage. To check next business day guarantee eligibility, enter the postcodes you’re sending to and from in the Australia Post Postage Calculator.

Registered Post

Registered post letters are perfect if shipping a special item, such as essential documents. Registered post includes a unique identification number that can be tracked and proof of posting if you send your letter from a post office. Registered post requires a signature upon delivery, ensuring your letter arrives safely at its destination. Compensation is given up to $100 for loss or damage, increasing to $5000 if you choose Extra Cover.

2. Weight and Dimensions

Postage costs for letters are determined by size, thickness and weight. Visit Australia Post’s letter size and weight guide to confirm if your item can be sent as a letter. Letter sizes and weights should fit into one of two groups:

Small Letters or Postcards

• up to 130mm x 240mm
• up to 5mm thick
• up to 250g
• Australia Post recommends that your letters be at least 88mm x 138mm to avoid getting lost or trapped in machinery.

Large Letters

• up to 260mm x 360mm
• up to 20mm thick
• up to 125g, 250g or 500g

If your letter exceeds the maximum weight or size, Australia Post will consider it a parcel, even if your delivery is packaged inside a letter. When this happens, your item (letter) moves into parcel territory, and prices can increase quickly. This is often where a courier service becomes a simpler, more cost-effective option, especially if your item is rigid and slightly bulky. Through Interparcel, you can compare parcel prices from multiple couriers in seconds, choose the best service for your budget, and book online with no contracts. Try our postage calculator whenever your item no longer qualifies as a letter.

An Overview of Australia Post Letter Services

There are many reasons for sending letters, from casual greeting cards to urgent legal documents, so it is natural that different items require different delivery services. This is why Australia Post offers a variety of different service choices, available for different prices.

Tip: If you’re unsure which Australia Post letter price applies to you, check the Australia Post Postage Calculator to compare regular, priority, express, and registered letter options in seconds.

Regular Letters

Your standard letter service. If you’re simply wondering, ‘How much does it cost to mail a letter?’ Then a regular letter is Australia Post’s most affordable, non-urgent mailing option. Perfect for everyday letters that don’t need to arrive by a set date. When sending regular letters, your primary concern needs to be working out the cost based on the size of your letter.

For regular Australia post letters, you can expect same-state delivery in 3-4 business days, and interstate delivery in 4-6 business days. This may take longer in peak periods.

Regular Letter Costs

• Small Letter or Postcard (up to 250g, dimensions up to 130mm x 240mm x 5mm) , $1.70
• Large Letter - Up to 125g (dimensions up to 260mm x 360mm x 20mm) , $3.40 (requires two $1.50 stamps)
• Large Letter - Up to 250g (dimensions up to 260mm x 360mm x 20mm) , $5.10 (requires three $1.50 stamps)
• Large Letter - Up to 500g (dimensions up to 260mm x 360mm x 20mm) , $8.50 (requires five $1.50 stamps)

Priority Letters

Australia Post’s priority letter service offers faster delivery than regular letters. It is suitable for punctual letters that must arrive before a specific date, such as a last-minute birthday card or an important bill. For priority letters, same-state delivery should arrive in 2-4 business days, while interstate delivery can take up to 4.

Priority Letter Costs

Priority service costs an additional $1.00 on top of regular letter rates.

• Small Letter (up to 250g) , $1.70 + $1.00 = $2.70
• Large Letter - 125g , $3.40 + $1.00 = $4.40
• Large Letter - 250g , $5.10 + $1.00 = $6.10
• Large Letter - 500g , $8.50 + $1.00 = $9.50

Express Post Letters

Express post next business day service is Australia Post's fastest option for sending letters, taking 1-3+ business days between most major metro areas.

Express Post Letter Costs

• Small DL Envelope (up to 500g and dimension up to 110mm x 220mm x 20mm) , $9.00 per envelope
• Medium C5 Envelope (up to 500g and dimension up tp 162mm x 229mm x 20mm) , $9.35 per envelope
• Large B4 Envelope (up to 500g and dimension up tp 250mm x 353mm x 20mm) , $11.05 per envelope

This service covers all Australian addresses and includes tracking and up to $100 compensation. You can also add optional extras like Signature on Delivery for $2.95 or Extra Cover for loss or damage up to $5,000.

Keep in mind that inflexible items such as keys, pens and USBs shouldn’t be sent in regular paper envelopes, as they can be damaged in the sorting process. These items need to be sent as a parcel in a tough bag or padded bag.

Seasonal Greeting Cards (Including Christmas Cards)

Seasonal greeting cards, including Christmas cards, can be sent at a reduced postage rate during November and December. This service offers a more affordable way to send festive messages during the busiest mailing season.

Seasonal Greeting Card Costs:

• Small Seasonal Card (up to 250g): $0.65
• Large Seasonal Card (up to 125g): $1.30

A Christmas card must be endorsed with ‘Card Only’ and sealed inside an envelope to qualify for the discounted rate. Available in November and December only.

Priority and Express Post options can still be used for faster delivery if you’re sending cards closer to Christmas.

Sending Christmas Cards Overseas

If you’re wondering whether Christmas cards can only be sent within Australia, the good news is that Australia Post makes it easy to share festive messages around the world. You can send Christmas cards to 220+ international destinations, giving you plenty of reach for family and friends overseas.

The international Christmas card postage rate is $3 via Economy Air, which typically takes 15+ business days.

To qualify for this rate, your card must be:

• Maximum size: 260mm x 360mm
• Maximum thickness: 5mm
• Maximum weight: 50g
• Sealed in an envelope and endorsed with ‘Card Only’

If you'd like a prepaid option, international prepaid postcards are also available for $3.10, which includes both the postcard and the postage.

Registered Post Letters

Registered post is the best postal method if you require enhanced security. It provides proof of posting and requires a signature upon delivery. This service is often used for legal documents, passports, and contracts, where signature on delivery and tracking are essential.

Registered Post Letter Costs

• DL Registered Post Prepaid Envelope (250g, 130mm x 240mm x 5mm) , $6.75
• B4 Registered Post Prepaid Envelope (500g, 250mm x 353mm x 20mm) , $8.80
• Registered Post Label (add-on for tracking) , $5.25

If you use prepaid envelopes regularly, you can save with a discount when buying in bulk.

Sending A Letter Internationally

No matter where you’re shipping in Australia, domestic letter postage rates remain the same based on the regular, priority, express, seasonal and registered options we have provided above.

However, international postage has a different pricing structure. Letter prices sometimes vary not only in size and weight but also on the country to which they are being sent.

Letters sent overseas can only contain printed material with no commercial value, otherwise, they must be declared a parcel. If your letter is larger than the maximum size and weight, it will also be considered a parcel.

If your letter exceeds the maximum size or weight, Australia Post will classify it as a parcel, and you’ll need to complete a customs form.

Like national letters, international letters fit into either a small or large size category and adhere to the same measurement and weight requirements.

International Letter Costs

Prepaid Envelopes / Postcards

• International Prepaid Postcards: Available for $3.10 to 220+ locations
• International Aerogrammes: Available for $3.35 to 220+ locations
• Air Mail Prepaid: Available for $4.30
• International Post Registered, available as a small envelope up to 500g for $21.55 per item and large for $33.45 per item.
• International Express, prices vary from $47.50 to $56.35, depending on location.

Always double-check the destination country’s postage zone using the Australia Post International Guide to ensure you apply the correct stamp value.

Paying With Stamps

When sending a letter, you may pay using a prepaid envelope, at a post office, or with postage stamps.

If you’re wondering 'how much does a postage stamp cost in Australia right now?' The standard rate for a small domestic letter is $1.70 as of 2025, up from $1.10 in previous years. Stamps have different values, and the cost of a stamp in Australia will vary depending on the value.

The most common stamp values are:

When using domestic stamps to pay for international mail, you must increase the amount by 10 per cent to pay GST. Alternatively, a range of special international stamps are available, which are GST-free.

A Step-by-Step Guide to Calculating Australia Post Letter Costs

The Australia Post Postage Calculator is a handy tool you can use to figure out the cost of sending a letter or parcel, as well as its estimated delivery time. The Postage Calculator works whether you’re sending interstate or internationally.

1. Visit Australia Post's Postage Calculator.
2. Using the bar at the top of the page, select whether you are shipping Within Australia or Overseas.
3. In the From section, type in your postcode.
4. In the To section, type the postcode of your destination. If you are shipping overseas, you can simply type in the country.
5. Click the red Go button, and you will be taken to a new page.
6. Switch from Parcels to Letters at the top of the page.
7. You will now be able to see the different postage options available, as well as the delivery estimates and lowest available prices.
8. You can click on a letter service to expand it. This will show you the different letter options available for each service, their prices and other options.
9. Select your optimal service based on the factors shown.
• For example, if you are sending a letter that weighs 300g, you will need a large letter (500g).
• Or, if you need your letter delivered within a few days, you may need to choose express post.
• Remember that the delivery estimate will change depending on your locations, so if you’re sending multiple letters, input new information for each one.
• Express post includes tracking and can be upgraded with a signature on delivery or extra cover, so if you’re shipping something important, this may be the choice for you.
10. Once you’ve found your chosen service, you’re ready to go. You can either pay and print at home or pay at your local Australia Post - the price will remain the same.

It’s the easiest way to confirm your Australia Post letter prices before mailing, ensuring you don’t underpay for postage.

Tips to Save Money When Mailing Letters with Australia Post

Mailing letters can add up, but Australia Post offers ways to save. Whether you’re an individual or a business, explore discounts, specialised accounts, and bulk options to cut costs. Here’s how!

• Use a MyPost Business Account
  Discounts are available for frequent mailers through the use of a MyPost Business Account.
• Use a MyPost Concession Account
  If you’re a concession card holder, you may be eligible for a free MyPost concession account, with discounted stamps.
• Buy Prepaid Envelopes in Bulk
  When purchasing bulk prepaid envelopes via Australia Post, you can get a discount.
• Mail Services for Businesses
  Australia Post offers full-rate mail, charity mail, promo post and clean mail options for bulk savings.
• Make sure you are correctly following the Australia Post guidelines
  Avoid unnecessary costs by ensuring that your letter is the correct size and you are using the right amount of stamps. Do not reuse stamps that have already been used. Failing to follow these guidelines can result in a fine or a refusal of delivery, costing you more in the long run.

If your business sends a high volume of letters, consider bulk-buying stamp rolls or prepaid envelopes during seasonal campaigns to lock in lower postage rates before annual price changes.

Addressing Your Letter Correctly

Whether it’s your first time sending a letter or your thousandth, it always pays to refresh on letter layouts. Using the correct layout ensures that your letters reach their correct destination with minimal delay.

Make Sure You Follow the Correct Envelope Zones

Australia Post uses advanced letter sorting technology to read addresses electronically, so it is important that when filling out an envelope, you include the required information in their specified zones.

1. Put the address of your letter’s destination in the ‘address zone’ in the centre of your envelope.
2. Address information should take up three or four lines and form a block of information with minimal line spacing.
   • Line 1 needs to contain the recipient's name, which can be an individual or a business. If the name of both a business and an individual is required, the business name should be used in line 1, and the recipient’s name will move to line 2.
   • Line 2 contains the destination’s street number and name or the Post Office Box/Locked Bag number.
   • Line 3 needs to state the locality or suburb, state and postcode. If shipping internationally, you must also include the country, which should be written in capitals.
3. A return to sender address should be included in the top left-hand corner ‘service zone’, or the back side of the envelope.

Tips to avoid delays and ensure your letters are delivered correctly:

• Write addresses as simply as possible - avoid using punctuation where you can.
• Print your writing and ensure that words and letters are spaced out for easy readability.
• If people have difficulty reading your handwriting, you can print the information and glue it to the envelope.
• If you make a mistake, don’t try to fix it. Start again with a new letter.
• Avoid using pens of unconventional colours, stick to blue or black.
• Double-check all details before sending your letter.

Mailing During Peak Seasons

Peak Season Delays

During peak seasons, such as around Christmas, Australia Post often works at high capacity, which can lead to delays. To ensure your letters arrive on time, post them a few days earlier than usual, or choose priority or express delivery.

Start Saving on Shipping

Australia Post offers a wide range of different letter services, perfect for both frequent and occasional senders.

By carefully considering your sending needs, you can save time and money while ensuring that your letter is delivered to its destination on time.

Knowing the correct Australia Post letter cost before you post prevents underpayment fees and helps you choose the best mix of speed and affordability.

The world of shipping may seem complicated, but for those willing to invest a little time in exploring shipping solutions, a wealth of savings and optimisations are available.

If you’d like to learn more, visit Interparcel or get in touch today for personalised advice on your mailing needs.

And if your business regularly uses Australia Post services, you can connect your Australia Post account to Interparcel and automate your entire fulfilment workflow. You’ll still use your existing rates, but gain access to powerful automation tools like printing manager, smart boxing, rule manager, and branded tracking, to name a few.

Here’s a quick overview of the Australia Post services Interparcel supports when you bring your Australia Post rates into our platform.

Frequently Asked Questions