SMS and messaging APIs
Each provider is profiled from its own pricing page, with the source recorded against every figure. The quoted rate is not the price: all three add US carrier fees on top, and two of the three publish the same carrier table, so the gap between them is smaller than either advertises. Two bill a segment rather than a message, which means a long text costs several times the figure on the card.
SMS and messaging APIs
| Provider | Outbound SMS, US | Carrier fees on top | What is metered |
|---|---|---|---|
| Plivo | $0.0077 per SMS sent to a US long code or short code, and $0.0079 toll-free. Inbound is the same. Carrier surcharge is separate. | Published in full on the pricing page itself: on a US long code, $0.0035 to AT&T, $0.0045 to T-Mobile and Verizon, and $0.005 to US Cellular and other networks. Verizon inbound is marked na rather than zero. | Pay as you go, quoted per SMS rather than per segment — the page's only segment footnote is about RCS, and the SMS table says nothing about character limits. Carrier surcharges apply to inbound and outbound usage on top. |
| Telnyx | $0.004 per message PART for outbound SMS, before the carrier passthrough. The unit is a part and not a message, so a text over one segment costs a multiple of this. | Passed through at cost on a separate published line, which Telnyx states is not marked up. Its own worked example puts the blended US carrier charge at $0.0038 a part — close to its own rate, so the carrier is roughly half the bill. | Two lines rather than one: Telnyx's own rate per message part, and the carrier's charge passed through at cost. Both are published and the company states the passthrough is not marked up. Volume tiers apply automatically at 100 million parts. |
| Twilio | $0.0083 per outbound segment sent to a US long code. Inbound is the same rate. The carrier fee is separate and roughly doubles it. | Added per message on top of the quoted rate, and published: on a US long code, $0.0035 to AT&T, $0.0045 to T-Mobile, $0.005 to US Cellular and $0.004 to all other carriers. Five separate tables cover long code, toll-free, short code, free-to-end-user short code and RCS. | Pay as you go per SEGMENT, not per message — a text longer than one segment is billed as several. Carrier fees are added on top of the quoted rate, US A2P 10DLC carries registration onboarding fees, and a message that ends in a failed status still costs $0.001. |
Which to consider
The cheapest number and a genuinely cheaper message. $0.50 a month for a US long code against Twilio's $1.15, and $0.0077 a message against $0.0083 — on an identical published carrier surcharge table, so the saving is real rather than an artefact of counting something different.
Wanting to see where the money goes. Telnyx publishes its own rate and the carrier passthrough as two separate lines and states the second is not marked up, with no platform fee and no support fee — the only one of the three that itemises the carrier's share rather than folding it in.
The most published detail in a market that publishes little. Its US carrier fees are broken out in five tables by number type, so the real cost of a segment is knowable before you send one — and the failed-message fee and 10DLC onboarding charge are stated rather than discovered on an invoice.