What will your messaging agent cost?
The same volume, priced across four ways of sending it. The useful output is not any single figure but the crossover: metered pricing wins at low volume and loses badly at scale, and a flat iMessage line does the opposite. Every rate below is sourced and dated, and where no neutral figure exists we say so instead of estimating one.
5,000 messages a month
| Channel | Per month | How that is worked out |
|---|---|---|
| iMessage, flat rate | $100 | One dedicated line at $100/month. Volume changes nothing. Cheapest published dedicated line. Others run to $289. On this provider, outbound messaging sits on an unpriced Enterprise tier. |
| iMessage, meteredCheapest here | $25.00 | Tier covering 6,000 messages. |
| SMS via Telnyx, registered | $52.25 | 5,000 × $0.004 provider rate plus about $0.00425 carrier pass-through, then $10/month campaign registration and $1 for the number. $0.004 a message part, $1.00 a number, carrier fees published separately and passed through. Carrier fees vary by destination carrier, so the figure used here is the midpoint of the published range rather than an exact price. |
| WhatsApp, United States | $125 | 5,000 × ≈$0.025 per message. Meta's base rate before any solution provider markup. Rates vary by conversation category, and Meta moved business agent pricing to a token model from August 2026. |
Where the answer flips
Metered iMessage starts at $5 a month for 250 messages, which is far cheaper than any flat line, and its published tiers stop at 15,000 messages for $50. Above that there is no published price at all.
A flat iMessage line is $100 a month and does not move, so it is poor value at a few hundred messages and the cheapest option here well before the metered tiers run out. SMS and WhatsApp both scale linearly with volume, which means they never stop growing: at high volume they are the expensive options even though they look cheapest at the bottom of the range.
That is the whole shape of this market. Below a few thousand messages, pay per message. Above ten to twenty thousand, buy a line and stop counting. The channel decision and the cost decision are the same decision, and almost nobody frames it that way.
What this does not include
Exact carrier fees. The SMS figure now includes the provider’s own published rate, but carrier pass-through varies by destination carrier across a published range, so the midpoint is used and labelled rather than presented as exact. Your bill will differ by a few tenths of a cent per message depending on who your recipients use.
RCS. Agent vetting through the Campaign Registry is $75, but per-message rates are only published by individual providers, so there is nothing neutral to compare against. It is omitted rather than guessed at.
Model inference, which is usually the cost people do remember, and one-off registration: $4 for 10DLC brand registration, and setup fees that run to $335 on one iMessage provider.
Sources: carrier pass-through and registration from the 10DLC guide, iMessage figures from the provider comparison, each taken from the provider’s own pricing page and dated there. WhatsApp rates are Meta’s published base rates before solution provider markup.