Second-line app vs verification number: which do you need?

A second-line app — what people often search as a burner app — gives you a phone number you keep: for calls, texts, and the login code a platform sends next year. A verification number is rented to receive one code, once, and then it's gone. Hushed, Burner, MySudo, TextNow and Google Voice sell the first kind; we sell the second.

That one distinction decides the purchase, so here it is before anything else: for a number you intend to keep, a second-line app or a second SIM is the right product — we are not. The rest of this page sorts out which job you actually have, because the two products are compared constantly and interchangeable never.

What a second-line app is

A second-line app puts an additional phone number inside an app on the phone you already own. The number persists: you give it out, call from it, text from it, and — while the line stays active — receive on it indefinitely. That last property is the whole point. A number that still answers in a year can carry an account's two-factor codes, sit on a listing you answer by phone, or front a side project for as long as it runs.

Hushed, Burner, MySudo, TextNow and Google Voice are the names people usually mean. We haven't audited any of them — pricing, coverage and what happens to your number when you stop paying are not verified by us and live on their own pages, so read the current terms there rather than taking a summary from a company that doesn't sell the product. The category-level trade, though, is stable: the number lasts exactly as long as the arrangement behind it, and no longer. An app line that lapses takes its number — and whatever accounts lean on it — along.

The other member of this family isn't an app at all: a second SIM, or an eSIM, in your existing phone. Same job, done by a carrier — a real mobile line you keep, subject to whatever registration rules your country applies to SIMs. Where a platform is suspicious of app-based ranges, it's the version of a kept number that behaves most like the one the platform expects.

What a verification number is

A verification number is rented for minutes, in a browser tab, to receive one SMS code. It makes no calls and sends no texts — receiving is all it does. When the rental ends the number returns to the pool, and messages don't linger either way: received messages are deleted from our side within 24 hours.

The job it does well is narrow: a platform wants a code before it lets you in, and you don't want to hand over the number your bank uses. One code, once. What is a burner number covers the wider family this product belongs to, and best SMS verification services lists the providers — ours included — without scores we can't back.

The limits are the mirror image of the second-line app's strengths. You can't call from it. You can't keep it. And if you attach it to an account you later need to recover, the platform will some day text a number you no longer hold — so the rule we repeat everywhere applies here with full force: never use a used-once number on an account you'd mind losing.

Which product for which job

The same split as a decision list. Choose a number you keep for:

• A line you hand out. Clients, a listing you answer by phone, anyone who might ring it twice.
• SMS two-factor. The platform will text this number at every login, indefinitely — it has to be a number that answers indefinitely.
• Any account you'd fight to recover. Banking, your main email, the social account with your history in it.
• A number you'll print or publish. Once it's out in the world, it needs to keep existing.

And a number you use once for:

• A signup you're trying out, where losing the account later would cost you nothing.
• Keeping your personal number out of a service's contact graph — the code arrives, the account exists, and your real number was never in the building.
• A one-off transaction where SMS is enough — a code to confirm, a message to arrange, nothing that needs a call back next month.
• Testing your own verification flow, in more countries than your desk drawer has SIMs.

When the honest answer is: not us

Plainly: if the job in front of you involves anyone reaching you on the number more than once, buy the kept kind — an app line or a second SIM — from someone who sells it. We don't. Nothing we rent persists, and selling you a used-once number for a keep-it job would buy us a refund request and you a locked account. A reader who arrived here comparing Hushed to a verification service almost always has a keep-it job, and the right page for them is the app's own site, not ours.

One thing worth checking before you commit to an app line: platforms can and do look up what kind of range a number sits on, and some treat app-based ranges differently from carrier SIMs. If a platform refuses an app number, that is the platform's rule rather than a defect in the app — and a carrier SIM is the fallback that looks most like the number the platform expects.