The numbers can be deleted whenever and you won’t be charged since you’re not using an actual telecommunications service. These are primarily for situations wherein you don’t want your main number being used-such as when socializing with strangers, signing up for online listings, filling out forms that may solicit ads, and whatnot. However, unlike second number apps such as 2ndLine, you can’t use these numbers to call and text your contacts. Plus, their service is free and all you need for them to work is an internet connection. Their validity will extend if someone contacts you using them. Take note that these have an expiration date of 7 days each.
The app lets you have up to three additional numbers on one SIM card-although you may not always max out that number due to app issues. Getting your free number here is easy, though.