Use the envelope guide bellow to select your required envelope size with the document you plan to enclose.

Also known as the seal flap, it is folded down and sealed after inserting contents.

Lick and Stick: Requires application of moisture to close.

Peel and Seal: Peel off plastic liner to expose glue strip, fold over and press to close.

Self Seal: Pre-gummed bottom flap for ease of closure, no moisture or plastic liner required.

Secretive envelopes have a printed internal pattern that prevents the contents in the envelope from being read through the envelope when held up against light. Non-Secretive envelopes are manufactured using unprinted envelope paper that does not have a printed pattern inside.

Plain face: No window to display the address on document enclosed.

Window face: Has a clear window on the front. Recommended for mail merge applications.

To be considered a letter, your item must:

✔  Weigh less than 500g

✔  Contain flexible items

✔  Have a rectangular shape

✔  Be no larger than a B4 envelope

✔  Be no thicker than 20mm

If your item were bigger than this they will classify it as a small or large parcel. Letters should not contain stiff objects such as bottle tops, pens, items enclosed in a hard case, and so on. High-speed letter sorting equipment could damage such objects, or the objects could damage other articles.

Australia Post - Postage Tips and Guidelines