Some names are written with an extra identifier, often because there were a few contemporaries with otherwise the same name. These government schemes have well indexed cross references although there is not one national index. Each state and each port of entry kept separate listings. Not all assisted migrants were British citizens. Some European migrants last century lived for a few years in England or Scotland before migrating to Australia on an assisted or a bonded voyage.
Unassisted migrants are sometimes fairly difficult to trace.
Deck or steerage passengers are not always listed on the ship's manifest by name. Cabin passengers are listed, but the vessel and date must be known. Voluntary groups are indexing the many names on unassisted shipping records but so far not many have been done. Legislation enacted in Britain in the 1840s permitted a simpler method to be administered in the Australian states. Naturalization remained under State authority until 1903, when it became a Commonwealth matter.