Anon SMS Journal
Temporary number vs Google Voice vs burner SIM vs eSIM: which one fits your situation
Four ways to get a phone number that isn't your phone number. Here is what each one costs, what it is genuinely good at, and the exact point where each one walls you out — including the one that catches most people, which is Google Voice being refused at verification.
By Ellis Marner · Delivery & privacy lead, Anon SMS
· 10 min read
First, work out which problem you actually have
Most of the bad advice in this area comes from four completely different needs being discussed as if they were one. Before comparing anything, decide which of these you have:
A number you keep long-term. A second line for work, side projects, or selling things — something people can call back next year.
A number you use once. A signup gate. You need a code to arrive, and after that the number never matters again.
A number in a specific country. An app that only accepts local numbers, a marketplace that is region-locked, a service that behaves differently outside its home market.
A number that is not tied to your identity. You want the account to exist without your permanent identifier attached to it.
The right tool is different for each, and a tool that is excellent for one is usually useless for another. That is the whole reason these comparisons get heated — people argue about the answer while holding different questions.
The comparison table
| Option | Upfront | Per use | Setup | Coverage | Works for verification? | Keeps the number? | Needs ID? |
|---|---|---|---|---|---|---|---|
| Google Voice | Free | Free | 10–20 min | US only | Often rejected (VoIP) | Yes, indefinitely | Existing US number |
| Second physical SIM | $5–30 + handset support | Monthly fee | Hours to days | One country | Almost always accepted | Yes, while you pay | Usually yes |
| Travel eSIM (Airalo, Ubigi) | $5–40 per plan | Included in data plan | 5–15 min | Many countries | Unreliable; often data-only | Only while the plan lasts | Sometimes |
| Temporary number service | None | Cents per code | Under a minute | 190+ countries | Yes, per service | No — minutes only | No |
Prices and acceptance rates drift; this table is reviewed quarterly and was last checked in August 2026.
Google Voice
What it is genuinely great at
Google Voice is the best free product in this category and it is not close. You get a permanent US number that does real voice calls, real SMS, voicemail with transcription, call forwarding to your actual handset, and a web and desktop client that works properly. It costs nothing, it never expires while you use it, and it is tied to an account you already have.
If what you want is a second number to give out — to clients, to marketplace buyers, on a CV, to people you would rather not hand your mobile to — and you are in the US, use Google Voice. Paying for anything else in that scenario is a waste of money.
The wall: VoIP rejection at verification
The problem appears the moment you try to use it as a verification number. Google Voice numbers sit in ranges that are publicly identifiable as VoIP, and a large share of services check exactly that. Anti-fraud vendors sell number-intelligence lookups that return line type — mobile, landline, VoIP — and blocking VoIP is one of the cheapest fraud controls available, because it restores the scarcity the number was supposed to provide.
Google Voice is the most widely blocked range of all, simply because it is the most widely used. The failure is also confusingly presented: sometimes an explicit "this number cannot be used", often just a code that never arrives. No configuration on your end changes this. It is a property of the number, not of your setup.
US-only, and it needs a number to begin with
Two further limits. Google Voice is available to US accounts with US numbers, so it is not an option elsewhere without workarounds we would not recommend. And setup requires linking an existing US mobile number — so it cannot be your first number, only your second. Long periods of inactivity can also cost you the number.
A second physical SIM
A prepaid SIM from a local carrier is the strongest possible answer to "will this be accepted?" It is a real mobile range, indistinguishable from anyone else's, and essentially never rejected. It receives every code, takes calls, and stays yours as long as you keep it topped up.
The costs are practical. You need a dual-SIM or eSIM-capable handset, or a second device. There is a monthly or minimum-top-up cost, small but permanent. And in most countries, prepaid SIM registration now requires identity documents — the UK is a notable exception, but across most of the EU, and in India, Indonesia, Nigeria, Brazil, Mexico, Australia and the Gulf, a passport or national ID is mandatory. That last point matters if your reason for wanting a second number was to avoid tying it to your identity: a registered SIM is arguably more strongly linked to you than your main one.
Choose this when the number is infrastructure — a business line, a landlord line, a number on a shopfront — and you will still want it in two years.
Travel eSIM apps
Airalo, Ubigi, Holafly and their competitors are excellent at the thing they advertise: cheap mobile data abroad without roaming charges. Install, scan a QR code, land, get data.
They are a poor and expensive mistake for verification, and the reason is buried in the plan details: most travel eSIM plans are data-only. They have no MSISDN — no phone number at all — so there is nothing for an SMS to be addressed to. Where a plan does include a number, inbound international SMS is frequently unsupported or unreliable, because the plan is provisioned through a roaming arrangement rather than as a local subscriber line. People buy a $20 eSIM specifically to receive one code, then discover it cannot receive any.
Use them for data. If you need a real local number while travelling, buy a local prepaid SIM on arrival or use a temporary number for the specific code you are chasing.
Temporary number services
A temporary number service rents you a number in a chosen country for the length of one verification. The code appears on screen, and the number is released. There is no subscription, no handset requirement, no ID, and the cost is cents rather than dollars. You can also pick the country deliberately, which is the only practical way to verify on a service that requires a local number in a market you are not in.
The honest limits: you do not keep the number, so it is the wrong tool for anything that might need future account recovery, and quality varies enormously between providers. Some resell exhausted number pools that services blocked years ago, and charge you anyway when nothing arrives. Our live per-service pricing is public for exactly that reason, and the service directory shows what is actually available before you spend anything.
How to tell a decent provider from a bad one
Four questions separate a working service from a number-shaped lottery ticket. They apply to us as much as to anyone else:
Do they charge when no code arrives? Delivery failure is normal and structural. A provider that keeps your money when the message never landed is charging you for its own routing failure — see our refund policy for what "no code, no charge" should look like in writing.
Is pricing visible before signup? If you have to deposit money to discover the price, the price is not the product.
Can you see live availability? Number pools are exhausted constantly. A provider showing a static country list rather than live stock is selling you a queue.
Is there a stated acceptable-use policy? A provider with no rules is a provider whose numbers are being used for fraud, which is precisely why services block their ranges — and why your code will not arrive.
Quick answers
- I want a permanent, free second US number
- Google Voice. It is free, it keeps the number indefinitely, and it does real calls and texts. Accept that a share of services will refuse it for verification because it is a VoIP range.
- I need to verify one account in Brazil tonight
- A temporary number service. It is the only option that gives you a local number in a specific country within a minute, for cents, with no contract and no ID.
- I need a work number I will use for the next two years
- A second physical SIM, or an eSIM voice plan from a local carrier. You want a real mobile range, inbound calls, and a number that is still yours in 2028.
- Google Voice was rejected by the service I am signing up to
- That service blocks VoIP number ranges. Nothing about your Google Voice setup will change that — use a real mobile range instead, either a second SIM or a temporary mobile number.
- I just need mobile data while travelling
- A travel eSIM such as Airalo or Ubigi. Do not buy one expecting to receive verification codes: most travel plans are data-only and cannot receive SMS at all.
- I do not want this signup linked to my real identity
- A temporary number removes one identifier, but your email, payment method and IP address remain. If unlinkability genuinely matters, the number is the easiest part of the problem, not the whole of it.
If the code still refuses to arrive after you have picked the right tool, the problem is usually the delivery chain rather than your choice of number — and the mechanics of a purchase are set out in how it works.
Read next
- Why every app wants your phone number (and what happens to it next)
A number stopped being a way to call you and became a persistent unique ID. Here are the four reasons a signup form asks for it, where it travels afterwards, and which risks are actually likely.
- Verification code not arriving? The 9 real reasons, and how to fix each one
An OTP crosses six hops before your phone buzzes, and any of them can drop it silently. The nine real causes, a five-minute triage order, and when the number itself is the problem.