Or you might be able select a combination of those factors, says Kenneally.What that allows you to do: Further ensure that the number would be useless to anyone but you.Use your own bookmark or type in the address yourself (and double-check your spelling).What you don't want to do: Click on a link that you receive in an email.
They may let you earmark the virtual number for a specific merchant.
And just because you can use one virtual number for multiple transactions or multiple merchants over a longer period of time, doesn't mean you should, says Foley.
Limiting its use -- to a short time period, or to one merchant -- is what makes a virtual number a valuable weapon against fraud and theft, he says.
Every issuer has its own system for handing out disposable numbers. Some tie disposable numbers to their online banking services and may require that you register for online banking to be able to use disposable numbers.
Others may have you log into their site when you need a virtual number.