Be patient and keep trying, it might show up after they turn it on.
But keep reading what else could have happened.
Recovery Failed: What Now?
So now your iPhone’s been missing for a while, and you haven’t been
able to track it down. The thief may have turned the phone off, erased
it or removed the SIM card. Or the thief is in another country, and
you’re getting no help from the authorities (and don’t want to get it
yourself). At this point tracking is unfortunately no longer an
option, and many people give up. Do not despair, for there is yet
If, for some reason, you didn’t set a SIM PIN, the first thing you’ll want to do is inform your phone provider/carrier to disable
your SIM and potentially save you many dollars of calls.
Next, file a police report and give them your device’s serial number and IMEI (phone only). Thieves occasionally get nabbed with a
whole bunch of stolen stuff, this way they’ll be able to return your
device to you.
You may want to consider wiping your device to ensure that your personal data does not fall into the wrong hands. You can remotely
wipe your device from within Find My iPhone, but note that once your
device is wiped, you will no longer be able to track it.
If you’re a corporate user and your iPhone/iPad is configured to sync with Exchange, you can also remotely wipe your device through
your Outlook Web Access (OWA). Simply log in, click Options in the top
right, then Mobile Devices in the left-hand menu, and finally select
the device you want to wipe and click Wipe All Data from Device.
The final step, to be taken when you’re pretty sure your phone will
never return, is to disable it so that it will be useless to anyone
else. In some countries can give your carrier your phone’s IMEI, and
they can blacklist it, essentially rendering the phone useless (nice
At that point if you do manage to get your phone
back, however, you won’t be able to use it as it’s not possible to
remove a device from the IMEI blacklist (to my knowledge). Note that
not all carriers in all countries are willing to add devices to the
(the US recently introduced a blacklist).