# How to Send a Letter in Australia: A Complete Guide (2026)

- Link: https://postmydoc.au/how-to-send-a-letter-in-australia/
- Published: 2026-05-17T16:21:31+09:30
- Author: PostMyDoc

![Clean editorial top-down composition showing the elements of sending a letter —
an envelope, a stamp positioned beside it, and a faint gesture of an addressing 
pen, on a soft neutral surface with subtle cyan accents on the stamp and addressing
area](https://postmydoc.au/wp-content/uploads/2026/05/Hero-How-to-Send-a-Letter-
in-Australia.png)

Guides

## How to Send a Letter in Australia: A Complete Guide (2026)

Published 17 May 2026 · 11 min read

New to sending physical mail, or out of practice? Here’s how to send a letter in
Australia — addresses, stamps, envelopes, weight — without overthinking it.

Contents

 1.  [What you need before you start](https://postmydoc.au/how-to-send-a-letter-in-australia/#what-you-need)
 2.  [What goes where on the envelope](https://postmydoc.au/how-to-send-a-letter-in-australia/#what-goes-where)
 3.  [How to write an Australian address](https://postmydoc.au/how-to-send-a-letter-in-australia/#address-format)
 4.  [Where to put your own address](https://postmydoc.au/how-to-send-a-letter-in-australia/#own-address)
 5.  [Envelopes: which size for what](https://postmydoc.au/how-to-send-a-letter-in-australia/#envelopes)
 6.  [Stamps: how many and how much](https://postmydoc.au/how-to-send-a-letter-in-australia/#stamps)
 7.  [How to estimate the weight without weighing](https://postmydoc.au/how-to-send-a-letter-in-australia/#weight)
 8.  [The size and weight cliff edges](https://postmydoc.au/how-to-send-a-letter-in-australia/#cliff-edges)
 9.  [Where to actually post the letter](https://postmydoc.au/how-to-send-a-letter-in-australia/#where-to-post)
 10. [A quick checklist before posting](https://postmydoc.au/how-to-send-a-letter-in-australia/#checklist)
 11. [Frequently asked questions](https://postmydoc.au/how-to-send-a-letter-in-australia/#faqs)

Sending a letter used to be one of those things everybody learned by watching their
parents do it. Address the envelope, stick on a stamp, drop it in the red post box
on the corner. You didn’t need a guide.

That’s not true anymore. A lot of adults — particularly anyone under thirty-five,
anyone who’s spent the last decade in fully digital communication, or anyone who
simply hasn’t sent a physical letter in years — has a perfectly reasonable moment
of _wait, how does this actually work?_ The instructions used to be common knowledge.
Now they’re a niche skill, like changing a tyre or reading a paper map.

Here’s the whole process, from blank envelope to postbox, with all the small details
Australia Post quietly assumes you already know.

## What you need before you start

You need an envelope, enough stamps, the recipient’s address, and either a printed
document or a handwritten letter to put inside it.

If you’re sending a printed document, you’ll need access to a printer. If you’re
sending a handwritten letter, you’ll just need paper. Either is fine — physical 
mail accepts both.

If you don’t have envelopes or stamps at home, **Officeworks** is the most cost-
effective one-stop — you can buy envelopes, stamps, and print your document there
in one trip, which is what makes it the practical choice for anyone who needs to
print and post in the same outing. Stamps and envelopes are also available at supermarkets
like Woolworths and Coles, most newsagents, and some service stations.

For convenience over cost, **the post office itself** is the alternative one-stop,
especially if you don’t need to print anything. Envelopes cost more there than at
Officeworks, but the staff can weigh your letter, advise on postage, and lodge it
on the spot. Post offices do not offer printing services — if you need to print,
that has to happen elsewhere first.

## What goes where on the envelope

![Clean editorial illustration of an envelope front showing the three address positions—
recipient address in the centre, sender address top-left, stamps in the top-right
corner — without literal text in those positions.](https://postmydoc.au/wp-content/
uploads/2026/05/Inline-1-Envelope-Layout-How-to-send-a-letter-in-Australia.png)

Three things go on the front of an envelope:

**The recipient’s address** sits in the centre or lower-centre of the front. This
is the address the letter is going _to_.

**Stamps** go in the top-right corner of the front. One stamp or several, depending
on weight (we’ll get to that).

**Your return address (the sender)** goes in the top-left corner of the front, or
on the back of the envelope. This is the address the letter would come back to if
it can’t be delivered. It’s not strictly required, but you absolutely want to include
it — without a return address, undeliverable mail is destroyed, not returned.

That’s the whole layout. The address goes in the middle, stamps top-right, your 
address top-left.

## How to write an Australian address

Australia uses a specific address format that differs from US, UK, and most European
formats. Get this right and the letter sorts cleanly. Get it wrong and it can be
delayed or misrouted.

The format is:

    ```pmd-rp-codeblock
    Recipient's Name
    Apartment/Unit Number (if applicable)
    Street Number and Street Name
    SUBURB STATE POSTCODE
    ```

A real example:

    ```pmd-rp-codeblock
    Sarah Chen
    14/45 Bourke Street
    SURRY HILLS NSW 2010
    ```

Three details people get wrong:

**The suburb, state, and postcode go on the same line.** Not three separate lines.
One line, in that order: suburb first, then state abbreviation, then postcode.

**The suburb and state should be in capital letters.** Australia Post uses optical
character recognition to sort mail, and the sorting machines read capital-letter
suburb names more reliably. Lowercase works but slows things down.

**State abbreviations are standard:** NSW (New South Wales), VIC (Victoria), QLD(
Queensland), WA (Western Australia), SA (South Australia), TAS (Tasmania), ACT (
Australian Capital Territory), NT (Northern Territory). Always use these abbreviations,
always in capitals.

If the apartment or unit number is separate from the street number, write it as `
unit/street` — for example, `14/45 Bourke Street` means unit 14 at street number
45. This is universal Australian convention.

For PO Boxes, the format is `PO Box 1234` on the line where you’d usually put the
street address. No street name needed.

## Where to put your own address

Two options, both acceptable:

**Top-left front of the envelope.** Same format as the recipient’s address, just
smaller and tucked into the corner. This is the more visible option and the standard
for business mail.

**The back of the envelope, on the flap or just below it.** Slightly more elegant
for personal letters, especially formal correspondence. Same format.

Either works. Just don’t skip it.

## Envelopes: which size for what

Australia Post categorises envelopes by _size_, not by name. But envelopes are _sold_
by name (DL, C5, C4, etc.), and the names don’t map cleanly to the categories.

![Editorial visual comparison of common Australian envelope sizes (DL, C5, C4) at
relative scale, with cyan highlighting which sizes fall into the small letter vs
large letter postal categories.](https://postmydoc.au/wp-content/uploads/2026/05/
Inline-2-Envelope-Size-Comparison-how-to-send-a-letter-in-Australia-.png)

The two Australia Post categories that matter:

**Small letter:** maximum 130 × 240mm, maximum 5mm thick, maximum 250g. Cheapest
postage rate. One stamp ($1.70) covers it.

**Large letter:** rectangular, maximum 260 × 360mm, maximum 20mm thick, maximum 
500g. More expensive. Multiple stamps required, with the number depending on weight.

Now the envelope sizes you’ll actually buy:

**DL envelope (110 × 220mm) and DLX envelope (120 × 235mm)** — the standard “business
envelopes.” Both fit an A4 page folded into thirds. Qualifies as a small letter 
as long as contents stay within 5mm thick and 250g. In practice: around 8–9 folded
A4 sheets is comfortable. Between 10 and 12 sheets, you’re in mindful-of-the-5mm-
limit territory — fold the creases carefully and flatten the document before sealing.
Beyond 12 sheets is risky; counter staff will sometimes reject thicker envelopes
on the spot, and red post box lodgement just means the underpaid-mail bill catches
up with you later. DLX gives a touch more room but most people don’t have those 
at home. **One $1.70 stamp** within those limits.

**C6 envelope (114 × 162mm)** — smaller, used for greeting cards and short notes.
Fits an A4 page folded twice. Qualifies as a small letter as long as contents stay
within 5mm thick and 250g. **One $1.70 stamp** within those limits.

**C5 envelope (162 × 229mm)** — fits an A4 page folded in half. Even though a C5
is smaller than C4, its 162mm width exceeds the 130mm small letter limit, which 
puts it into the **large letter** category. **Two $1.70 stamps minimum.** Both the
envelope size and the weight matter for pricing — the envelope determines that it’s
a large letter (rather than a small letter), and the weight then determines which
large letter tier applies (two stamps up to 125g, three up to 250g, five up to 500g).
A nearly empty C5 with one folded sheet inside still costs $3.40 because the envelope
size alone is enough to put it in the lowest large letter tier.

**C4 envelope (229 × 324mm)** — fits an unfolded A4 page. Always a large letter (
the envelope size puts it there). The specific number of stamps depends on weight:**
two $1.70 stamps** for contents up to 125g (roughly 24 single-sided A4 sheets including
envelope), **three stamps** for 126–250g, **five stamps** for 251–500g. Most multi-
page documents in a C4 land in the two- or three-stamp range.

**B4 envelope (250 × 353mm)** — slightly larger than C4, with more room. Also always
a large letter. Same weight-based stamp scale: two, three, or five $1.70 stamps 
depending on weight.

The practical implication: if you’re sending an A4 document and you want the cheapest
rate, fold it into thirds and use a DL envelope. If you fold it in half and use 
a C5, you pay double. Folding into thirds is standard professional practice for 
business letters precisely because it qualifies for the small letter rate.

A consideration that runs the other way, though: some documents shouldn’t be folded
at all. Signed contracts, formal letters on letterhead, CVs being couriered to an
interview, certificates, anything where the document’s presentation is part of its
message — these benefit from arriving flat. The cost saving from folding into thirds
is real, but for documents where the fold itself would feel inappropriate, the right
call is a C4 or B4 envelope (large letter rate) even though it costs more. Match
the envelope to the document’s purpose, not just to the cheapest rate.

## Stamps: how many and how much

Australia Post’s current rates (since 17 July 2025):

**Small letter:** $1.70. One stamp covers it, _as long as_ the envelope stays within
all three small letter limits — 130 × 240mm, 5mm thick, 250g. If it exceeds any 
one of these (most often thickness, before weight), it’s no longer a small letter
and the large letter rates below apply.

**Large letter up to 125g:** $3.40. **Two $1.70 stamps.**

**Large letter, 126–250g:** $5.10. **Three $1.70 stamps.**

**Large letter, 251–500g:** $8.50. **Five $1.70 stamps.**

That’s the whole rate card for regular domestic mail. (Australia Post has proposed
raising the basic small letter rate to $1.85 in mid-to-late 2026, pending ACCC approval,
so these prices will likely shift.)

If you need a letter to arrive faster, **Priority** adds $1.00 to any of the above
rates and aims for delivery 2–4 business days same-state, up to 4 days interstate.
To use Priority, place a Priority label next to your stamps.

For genuinely time-sensitive mail, **Express Post** is the premium tier. Express
Post envelopes are prepaid and sold individually — they include the postage in the
envelope price. The standard option for most documents is a **DL Express Post envelope
at $9.00**, which holds up to 500g and fits an A4 document folded into thirds. The**
B4 Express Post envelope at around $11.05** is the right choice when you don’t want
the document folded — for signed contracts, formal letters on letterhead, CVs, certificates,
or anything where the fold itself would undermine the document’s presentation. B4
also handles larger or thicker items. Both DL and B4 Express Post aim for next-business-
day delivery between most metro areas.

## How to estimate the weight without weighing it

Most people don’t own postage scales. Fortunately, the weight of a letter is easy
to estimate with reasonable accuracy.

**Standard 80gsm A4 paper weighs almost exactly 5 grams per sheet.** This is the
most useful number to know when sending letters. The maths: an A4 sheet is 297 ×
210mm, which is 0.0624 square metres. Standard 80gsm paper weighs 80 grams per square
metre. Multiply: 4.99 grams per sheet. Round to 5.

**A standard DL envelope weighs around 5 grams.** Larger envelopes scale up — a 
C4 envelope is around 10–15 grams.

So a quick mental calculation:

 * 1-page letter in a DL envelope: 5 + 5 = **~10g** (small letter, $1.70)
 * 3-page letter folded into a DL envelope: 15 + 5 = **~20g** (small letter, $1.70)
 * 8-page document folded into a DL envelope: 40 + 5 = **~45g** (small letter, $
   1.70 — comfortable thickness)
 * 10-page document folded into a DL envelope: 50 + 5 = **~55g** (still small letter
   by weight, but at the edge of the 5mm thickness limit — fold and flatten carefully)
 * 15-page document in a C4 envelope (won’t fit DL by thickness): 75 + 12 = **~87g**(
   large letter up to 125g rate, $3.40)
 * 25-page document in a C4 envelope: 125 + 12 = **~137g** (now in 126–250g tier,
   $5.10)
 * 30-page document in a C4 envelope: 150 + 12 = **~162g** (same 126–250g tier, 
   $5.10)

A useful trick for heavier documents: **print double-sided where possible.** A 20-
page document printed double-sided becomes 10 physical sheets at ~50g, instead of
20 sheets at ~100g. That can keep you under a pricing threshold and save real money
on bulk mail-outs.

## The size and weight cliff edges that cost people money

A few specific traps worth knowing:

**Thickness over 5mm pushes you from small letter to large letter.** This happens
faster than you’d think. A few folded pages, or a card with a folded insert, can
easily exceed 5mm. If your envelope doesn’t lie flat at letterbox-slot thickness,
it’s a large letter — minimum $3.40 (two stamps), regardless of weight. For most
small-letter senders, this is the cliff that actually triggers first, because envelope
dimensions usually mean you’d hit 5mm thick well before approaching the 250g weight
limit.

**Within the large letter category, watch the 125g and 250g tier boundaries.** A
large letter goes from $3.40 to $5.10 once contents exceed 125g — a 50% increase
for one extra stamp. From $5.10 to $8.50 once contents exceed 250g — a 67% increase,
two more stamps. If you’re close to either threshold, it’s worth weighing more carefully
or printing double-sided to stay in the cheaper tier.

**Anything over 500g, or thicker than 20mm, or larger than 260 × 360mm, is a parcel.**
Parcels start at $9.70 — almost 6× the small letter rate. This is the biggest pricing
cliff. A 22mm-thick envelope that looks like a thick letter is, by Australia Post’s
rules, a parcel. Different stamps, different counter, different rate.

**Inflexible items can’t go in a letter envelope at all.** Keys, USBs, pens, bottle
tops, anything rigid — these can’t be sent in regular paper envelopes because the
high-speed letter-sorting machinery can damage them and the rest of the mail in 
the same batch. If you’re sending anything with rigid bulk, it needs a padded bag
and goes as a parcel.

## Where to actually post the letter

Once your envelope is addressed, stamped, and sealed, you have two options:

**A red Australia Post street box.** Found on streetcorners across the country. 
For regular letters with stamps, just drop it in the slot. The box is collected 
daily on business days. Small letters and large letters both go here.

**A post office.** Required for anything tracked (Registered Post, Express Post 
with signature), anything you want a receipt for, and any parcel. Optional but useful
if you’re not sure your letter is correctly stamped — the staff can weigh it and
tell you whether you need more postage.

If you’re using a prepaid envelope (Express Post or Registered Post), you can lodge
it in a street box or at a post office. Prepaid envelopes don’t need additional 
stamps because the postage is built into the envelope price.

This guide assumes a red post box or a post office is reasonably reachable from 
where you are. If you’re rural, remote, or in a part of a city where neither is 
convenient and you don’t drive, your options change. That’s a different post.

## A quick checklist before posting

If you’re sending a letter and want to make sure you haven’t missed anything:

 1. Recipient’s address written clearly, suburb/state/postcode on one line in capitals
 2. Sender’s address on the front top-left or on the back of the envelope
 3. Correct stamps in the top-right corner — one $1.70 stamp for small letters, two
    or more for large letters depending on weight
 4. Envelope sealed (lick the gum strip or use a self-seal flap)
 5. Postage stamps actually stuck on, not just placed loose

Drop it in the box.

## Frequently asked questions

Do I need to include the country if I’m posting within Australia?

No. Australian mail doesn’t need the country. If you’re posting _to_ Australia from
another country, you need to add `AUSTRALIA` in capitals on the bottom line.

Can I send cash in a letter?

You can, but you shouldn’t. Australia Post doesn’t insure cash sent in regular mail,
and untracked letters offer no recourse if the envelope is lost or interfered with.
Use a money order, bank transfer, or PayID for transferring money.

What if I put the wrong stamp value on?

If you underpay, Australia Post will usually deliver the letter anyway and send 
you an Underpaid Mail invoice for the shortfall plus an administration fee. In some
cases they may hold the item until the correct postage is paid, or charge the recipient
if they can’t identify the sender from the envelope. This is one reason a return
address matters. Overpaying is fine — you’ve just spent more than you needed to.

Does writing in pen vs typing matter?

For the addresses, typed or printed labels are slightly more reliable for the sorting
machinery, but handwritten addresses are completely standard and accepted. Just 
make sure the handwriting is legible, particularly the postcode.

Can I post a letter on a Sunday?

You can put it in a street box on Sunday — it just won’t be collected until Monday.
Australia Post collects from street boxes on business days only.

What if the recipient is overseas?

International mail is a different process, with different envelopes, different postage
rates by destination zone, and customs declarations for most services. We’ve covered
that separately in [how to send a letter overseas from Australia](https://postmydoc.au/how-to-send-a-letter-overseas-from-australia/).

Are stamps the same as prepaid envelopes?

No. A stamp is postage you stick onto a regular envelope you’ve supplied yourself.
A prepaid envelope is sold with the postage already built in — you don’t add stamps.
Prepaid envelopes are slightly more expensive than buying the envelope and stamps
separately, but they include features like tracking (for Registered Post) or express
service (for Express Post).

Do I really need the postcode?

Yes. The postcode is what tells Australia Post’s sorting system where the letter
is going. Without it, the letter is sorted manually based on the suburb name, which
is slower and more error-prone. Always include the postcode.

If you’d rather not have to remember any of this — what size envelope, how many 
stamps, where things go on the front, whether you’ve got enough weight margin to
add another page — [PostMyDoc handles it](https://postmydoc.au/send-a-document/).
You upload a PDF, we print it, choose the right envelope, calculate the postage,
and lodge it with Australia Post. The whole process this guide just described, handled
at our end. You get the outcome; you don’t have to think about the process.

 [Send a document](https://postmydoc.au/send-a-document/) [Read about Burn After Reading](https://postmydoc.au/burn-after-reading/)

For everyone else: now you know where the stamps go.

Last updated: 17 May 2026

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