Traveling abroad

I got the $30 monthly plan that is used to buy internet, so I should probably make a refill right before coming back to the states around March 1st, right?

Yes. Since you have a $30 plan, that $30 got used to renew your plan when it expired. Even if the plan was already expired and the $30 got used immediately on Dec 5, your account and number should still be safe until Mar 5 but I wouldn’t cut it that close to refill. Mar 1 would be good.

That depends on what your expiration date was changed to when you topped off. A prepaid account is automatically closed if the account balance is $0 for more than 60 days after service expires. If your refill was less than $24, that extended your expiration date 30 days. If your refill was $24-$99, that extended your expiration date 90 days. Bottom line, you have 60 days after your balance is expired or used. When your balance expires, it is lost.  If you don’t want your balance to expire, refill before the expiration date.

I made a $30 refill on Dec 5, would this mean that the number would be valid through March 5th or February 5th then?

Your expiration date should be Mar 5 unless the $30 got used to pay for a plan, that’s 90 days from Dec 5. Your number will be valid through at least Mar 5, maybe longer. That all depends on when the balance expires or got used to pay for a plan. What plan do you have? 

I got the $30 monthly plan that is used to buy internet, so I should probably make a refill right before coming back to the states around March 1st, right? All I want is to keep my number active

Thank you very much, you've been of great help