You sure can use another SIM when traveling, in fact I recommend that you use a SIM card from the local provider in the country you are traveling to.
As far as switching back to the Verizon SIM, that is not really necessary as while on the Verizon network your BB 9930 is not using the SIM card that is installed. In fact, on my BB 9650 I have my Verizon SIM turned backwards to prevent the network identification messages that it caused when rebooting.
It would be my pleasure to discuss the options you have with the SIM card capabilities of your device! The SIM card slot can be unlocked for use with other carriers SIM cards while travelling internationally. There are a variety of requirements that would have to be met. You must be a current Verizon Wireless customer with the line activated for longer than 60 days. You must also have a current account balance with no recent history of past due payments. To review your eligibility further, please reach out to our Global Support Team at 800-711-8300. Please do not hesitate to reach out if you have any other questions or concerns.
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