In Indonesia, I have to register SIM card with government.
I have 4 cats. I have no idea how should I have 4 sim cards.
So I wonder if there is a GPS tracker without sim card?
There are projects like Findster providing similar functionality based on 1kHz radio frequency, which is open to the general public in most countries. However, it's important to note that the range is limited to around 1km (at least on the original model; don't have any experience with the newer revisions).
That would only be sensibly possible if you were only able to get a log of locations/routes after physical retrieval of the tracker, ie.you have got your collar back. If you want 'real-time' tracking, then the GPS position data has to be transmitted to a server, and then to you. The cellular networks are the only pervasive, cheap-ish, power-effective means of providing that link, and the service providers need to provide a SIM card. Does your government restrict you to registering only one SIM card per person? Seems a bit harsh:(
How would that tracker report the location of your pet if there were no functionality to do so?
Which is exactly why that SIM card is needed, to connect to a cellular network so the tracker can send its (and by proxy that of the pet that's wearing it) to a server and from there to you.
So no, it's highly unlikely to find one that doesn't require this, at least not one that's in any way useful outside the confines of your own home (where you could have it connect to your home wifi for example, something not universally applicable as there are no city wide (let alone nation wide) open wifi networks).
Technically it's possible to use other communications technologies, but they're far more expensive and both power requirements and weight of the device would go up a lot, think satellite phones (which no doube are restricted where ever cellphones are restricted).
All are good answer. Technically, only Mario' answer is an answer. However the other answers are very good and explains WHY we need the SIM card.
I just want to post another one
It uses bluetooth like tile.