Phone number APIs for receiving SMS, compared

For a US number that only needs to receive SMS, the published list prices on 7 October 2026 run from $0.50 to $1.15 a month for the number and from $0.004 to $0.0083 per inbound message. Plivo has the cheapest number and Telnyx the cheapest inbound message. Twilio and Sinch were the only two with a test mode documented on the pages we read.

Those prices cover four of the six communications API providers compared here. The Vonage and Bandwidth pricing pages returned an error (HTTP 403) when we opened them on 7 October 2026, so their figures below come from secondary sources and are marked. A separate category, short-term rental services, sells receive-only numbers by the activation or by the week, and it needs its own section because its prices, terms and risks are different.

What the six providers charge to receive an SMSCopy Anchor Link

Plivo is cheapest for the number and Telnyx is cheapest per message, on US list prices displayed on 7 October 2026. All prices are for a local (10-digit long code) number and exclude the surcharges that mobile carriers add.

Twilio prices SMS by usage and publishes its rates per country. Screenshot of twilio.com, taken on 7 October 2026.

Three details change the real bill.

Carriers add an inbound surcharge. Twilio and Plivo both list an inbound carrier fee of $0.0035 per SMS from AT&T and $0.0025 from T-Mobile, and Telnyx lists $0.0035 per message part from AT&T (Twilio, Plivo, Telnyx, all as displayed 7 October 2026). On the Telnyx base rate of $0.004, a $0.0035 surcharge nearly doubles the cost of that message.

Plivo lists what it charges to send and to receive an SMS on each route type. Screenshot of plivo.com, taken on 7 October 2026.

Long messages count more than once. Twilio bills per segment and Telnyx per message part, so a long text is charged as several.

Volume decides the winner. Using only the base rates in the table, 100 inbound messages a month costs about $1.27 at Plivo, $1.40 at Telnyx, $1.78 at Sinch and $1.98 at Twilio. At 5,000 a month the order changes: about $21.00 at Telnyx, $39.00 at Plivo, $40.00 at Sinch and $42.65 at Twilio. Telnyx overtakes Plivo at roughly 135 messages a month. This is our arithmetic on the list prices above, before surcharges, volume discounts and the Sinch setup fee.

Twilio also charges $0.50 a month for a number you bring yourself, against $1.15 for one it leases to you (Twilio pricing, October 2026).

Test modes: what you can try before payingCopy Anchor Link

Sinch and Twilio document a test mode on the pages we read, and only the Sinch one is described as covering inbound messages.

• Sinch says its sandbox "is included with every free developer account" and lists "Inbound message simulation" and simulated delivery reports among its features (Sinch texting sandbox).
• Twilio issues test credentials. With them, Twilio "doesn't charge your account, update the state of your account, or connect to real phone numbers." They cover buying a number, sending an SMS, making a call and Lookup, and they use magic values such as +15005550006 for a valid number. Messages sent with them do not trigger status callbacks, and the page does not describe simulating an inbound SMS (Twilio test credentials).
• Telnyx, Plivo, Vonage and Bandwidth: a dedicated sandbox was not found on the pages we opened. That is not evidence that none exists, and we did not verify any trial credit amounts, so we quote none.

If your product's core path is "a message arrives and my code reacts", check that the test mode can produce an inbound event. The Twilio test credentials page, for example, only describes outbound actions.

How inbound messages reach your codeCopy Anchor Link

The four providers whose documentation we read deliver an inbound SMS by calling a webhook URL you set, and the differences are in timeouts, retries and signatures.

The practical consequences are the same everywhere. Acknowledge fast and do the work afterwards, because a 2-second deadline leaves little room for slow work inside the handler. Verify the signature where one exists. Store the message id and skip repeats, because 24 hours of retries will deliver duplicates. Our guide to idempotency keys and webhooks for reseller APIs covers the pattern in detail.

Registration burden: 10DLCCopy Anchor Link

10DLC registration is a rule about sending, and no primary page we read says plainly whether a receive-only number is exempt. Twilio's wording is: "Anyone sending SMS/MMS messages over a 10DLC number from an application to the US must register for A2P 10DLC", and it includes individuals and hobbyists (Twilio A2P 10DLC docs). Telnyx states that "From February 3rd 2025, any 10DLC traffic which is not registered will be blocked altogether" (Telnyx 10DLC FAQ). Neither page addresses a number that never sends.

So plan on two cases. If the number only receives, ask the provider in writing before you rely on it. If your application ever replies, even with a one-line confirmation, registration applies, and the costs are:

A $10 monthly campaign fee is ten times a $1.00 number rental. For a low-volume project, registration can cost more than the number and the messages combined. Fee schedules for Plivo, Sinch, Vonage and Bandwidth were not found on the pages we opened.

If you sell numbers to your own customers, registration works differently: Twilio treats software vendors as a separate case and points them to their own registration guides (Twilio A2P 10DLC docs). That case is covered in Twilio alternatives for reselling phone numbers.

Short-term rental services: a different productCopy Anchor Link

Short-term rental services sell a receive-only number per activation or per rental period, with no monthly-plus-usage bill and no sending.

What this category offers: numbers in many countries without a contract with a communications provider, lines that TextVerified and quackr describe as non-VoIP, and rentals measured in days. What it lacks: sending, and the documented retry and delivery behaviour described above. Every claim in the table is the vendor's own, and we found no independent data on delivery success rates for any of them.

Continuity is a real risk. DaisySMS, a vendor in this category, announced its closure on 24 February 2026, and its site now reads "DaisySMS has shut down on March 26, 2026" (DaisySMS). If you prepay a balance with a vendor in this category, keep it small.

Legitimate uses and the limits in the termsCopy Anchor Link

The defensible use of a rented receive-only number is to test or operate something you are entitled to operate, and the vendors' own terms prohibit the rest.

Uses the vendors themselves list:

• Software testing and QA (5SIM).
• Protecting a personal number "from data breaches, spam, and resale" (TextVerified).
• Keeping work and personal messages apart, and receiving messages while travelling (5SIM).

Limits written into the terms:

• TextVerified says "Use of our services to engage in or promote illegal activities is strictly prohibited" and "Sharing these numbers to third parties is prohibited", which appears to rule out simple resale. The terms page carries no date. It also says purchases made with cryptocurrency may not be refunded (TextVerified terms).
• quackr prohibits "Automated sign-ups or multiple free/trial accounts to evade limits" and may suspend or terminate "any account, number, eSIM, or feature at any time, with or without notice", with no refund where the suspension follows a breach (quackr terms, last updated 23 July 2026).
• 5SIM says the service "is intended for lawful use only" (5SIM).
• Twilio's Acceptable Use Policy, last updated 12 May 2025, prohibits "Creating a false identity or any attempt to mislead others as to the identity of the sender or the origin of any data or communications" (Twilio AUP).

There is a second layer the number vendor cannot waive: the terms of the service that sends the code. A vendor allowing you to receive a verification SMS does not mean the sending service allows accounts verified that way. We did not open the terms of the large consumer platforms for this article, so we quote none of them; read the one that applies to you.

Misuse of this category has led to prosecutions. In October 2025, Europol's Operation SIMCARTEL led to 7 arrests and the seizure of 1,200 SIM-box devices holding 40,000 active SIM cards, behind a rental service linked to more than 49 million online accounts (The Hacker News, 19 October 2025, reporting Europol's announcement).

How to chooseCopy Anchor Link

Pick by what the number has to do, not by the headline price.

• Receive and reply, at volume, in the US: a communications API provider. On list prices Telnyx is cheapest per message and Plivo per number. Budget for 10DLC.
• Integration tests of an inbound flow: start with a simulated sandbox such as Sinch's before renting anything.
• A number for days, or in a country where you have no provider relationship: a rental service, with a small prepaid balance and a careful read of the terms.
• Codes from a service that rejects VoIP lines: ask the provider how its numbers are classified, because none of the six pricing or documentation pages we read says. A rental sold as non-VoIP may work, subject to that service's terms.

Where ResellerHQ fitsCopy Anchor Link

ResellerHQ, which publishes this blog, is a white-label reseller API that sits in the rental category, not the communications API one: it rents receive-only numbers from upstream providers for fixed periods from 12 hours to 365 days and posts each message to your endpoint as a signed number.message.received webhook (docs). Numbers cannot send. It fits if you want to sell rented numbers under your own brand from a prepaid wallet, and it does not fit if you need two-way messaging.

The platform is in early access, live numbers depend on an upstream provider being enabled on your account, and there is no public price list; you see your price from the offers endpoint once you have an account. The sandbox issues test numbers that never receive real SMS, though you can send them a test message from the dashboard and the webhooks are signed and delivered as they would be live. Accounts are created at /signup and start in the sandbox.