Postscript Pricing: Tiers, Carrier Fees and Extras

Postscript pricing looks simple on the vendor’s own page: four tiers, a monthly base fee, and a per-message rate that steps down as you move up. What that page doesn’t put in the same font size is that every message — campaign or flow, SMS or MMS — also carries a carrier fee billed as a separate line, and that a dedicated short code adds a flat $750 a month on top of whichever tier you’re paying for. For a $3M–$30M brand running SMS at real volume, the gap between the advertised rate and the number that actually lands on the invoice is where the monthly budget quietly moves — and it moves by more each month volume grows, because the hidden lines scale with sending rather than staying fixed.

This piece works from Postscript’s own pricing page and its own carrier-fee documentation, both checked in September 2026, to build the two things that page doesn’t show: the all-in cost per message once carrier fees are added, and what a given subscriber count and send volume actually costs in a month. Every figure below traces to one of those two vendor pages or is computed directly from them — nothing is estimated from a third-party round-up.

What does Postscript pricing actually cost per month?

Postscript runs four tiers, priced on a monthly base fee plus a per-message rate that falls as the base rises:

Source: Postscript’s pricing page, checked September 2026. Figures are the vendor’s own published rates.

Two things on that table are easy to misread. First, Starter’s “$0 base fee” is not free SMS — it carries a $49 minimum monthly spend, so a brand sending fewer than roughly 5,400 messages a month (the point at which $0.009-per-SMS usage crosses $49) is paying the floor rather than the metered rate. Second, the toll-free number is genuinely included at every tier — Postscript provisions and carrier-verifies it at no charge — which is the one line item on this table that isn’t hiding anything.

None of the four rows include a carrier fee. That’s the next section.

What hidden line items does Postscript’s published price leave out?

Every message that reaches a US or Canadian mobile number carries a carrier fee, billed by Postscript as a separate line from the plan’s per-message rate. Postscript’s own carrier-fee documentation gives a blended US average of $0.00418 per SMS and $0.00841 per MMS, and breaks the fee down by carrier:

Source: Postscript Help Center, “Understanding Carrier Fees,” checked September 2026. Verizon’s outbound SMS fee is scheduled to rise from $0.0045 to $0.0050 on toll-free and short-code sends effective 1 October 2026; MMS and inbound rates are unaffected by that change.

Postscript states it passes these fees through at cost, with no markup — the vendor doesn’t profit on the carrier line, but the merchant still pays it, and it doesn’t appear anywhere on the pricing page’s headline rates.

A dedicated short code is the second hidden line: $750 a month, charged at the carriers’ own rate with no Postscript markup, for brands that move off the shared toll-free number for higher sending throughput. It’s a flat fee, not a per-message one, so it hits a low-volume sender proportionally harder than a high-volume one. International sending carries its own carrier pricing too — Postscript’s public fee schedule is scoped to US and Canadian carriers, so the actual per-message cost for a meaningfully international list is — metric to confirm, and worth confirming with Postscript directly before assuming domestic rates apply.

Message length adds a third, quieter cost that has nothing to do with Postscript’s rate card and everything to do with how SMS itself works. A standard SMS segment is capped at 160 characters when it’s encoded in plain GSM-7 text. The moment a message contains a character GSM-7 can’t represent — an emoji, a curly apostrophe, an em dash, most accented letters — the whole message switches to Unicode encoding, and the per-segment limit drops to 70 characters. A promo text with a discount code, a product name and one emoji can silently cross that boundary and split into two billed segments instead of one, doubling both the platform rate and the carrier fee for that send without changing what the subscriber sees as “one text.” Reviewing flow copy for accidental Unicode characters before a send is free; finding out from the bill that a campaign billed as two segments per subscriber is not.

How much will Postscript actually cost at your subscriber count and send volume?

Nobody publishes this number, because it depends on your list size and your sending cadence, not on Postscript’s plan. The method is the same regardless of the inputs:

1. Count active SMS subscribers — opted in, not unsubscribed.
2. Multiply by the number of full-list campaign sends you plan to run in a month.
3. Add flow-triggered messages: abandoned-cart, post-purchase, back-in-stock and any other automation, each multiplied by its own monthly trigger volume.
4. Multiply the total message count by the tier’s all-in SMS rate (the per-message rate plus the carrier fee — the next section gives that number per tier).
5. Add the MMS line separately, at the MMS all-in rate, for any messages sent with an image.
6. Add the monthly base fee, and the $750 short-code fee if you’re on one.

Here is that method worked through with invented inputs, illustrative only and not a measured average — swap in your own subscriber count and cadence:

A brand on the Professional plan with 25,000 active SMS subscribers, running eight full-list campaigns a month and no MMS in this pass:

Adding 2,000 MMS sends in the same month, at Professional’s all-in MMS rate of $0.03241 ($0.024 platform plus $0.00841 carrier), adds $64.82 — bringing the illustrative total to $2,800.82. Add $750 on top if that volume is running through a dedicated short code rather than the included toll-free number, for an illustrative total cost of ownership of $3,550.82: one number standing in for four line items — platform base, metered SMS, metered MMS and the short code — that Postscript bills as four separate entries rather than one.

A smaller brand on Growth tells a different story with the same method. Illustrative inputs again: 8,000 active SMS subscribers, five full-list campaigns a month, no MMS and no short code.

The arithmetic scales linearly with volume once you’re inside a tier — double the subscriber count or the send frequency and the SMS line roughly doubles, because the all-in rate per message doesn’t change until you cross into a different tier. That crossover is where the platform’s own pricing page has nothing to say, which the next section fixes.

What is the real all-in cost per message once carrier fees are included?

Combining each tier’s published per-message rate with Postscript’s own stated blended carrier fee gives the number the pricing page never states directly:

Computed here from Postscript’s own published platform rates and its own stated blended carrier-fee average, both checked September 2026. The carrier fee is the same in dollars per message on every tier, so it narrows the percentage gap between tiers even as the platform rate falls.

At Starter, the carrier fee adds roughly 46% on top of the advertised $0.009 rate. At Professional, the same $0.00418 adds roughly 60% on top of a lower $0.007 rate — the discount for moving up a tier is real, but it’s a discount on the smaller half of the true per-message cost, not on the whole thing.

When does upgrading from Growth to Professional actually pay for itself?

Working out when an upgrade pays for itself is arithmetic Postscript’s pricing page leaves for the merchant to do. Moving from Growth to Professional adds $400 a month to the base fee ($500 minus $100) and saves $0.001 on every SMS ($0.008 minus $0.007). The carrier fee is identical on both tiers, so it cancels out of the comparison entirely — the breakeven depends only on the platform rates:

Below 400,000 SMS a month, staying on Growth and paying the higher per-message rate costs less overall than moving to Professional for the lower rate. A brand sending 200,000 SMS a month is paying more on Professional than it would on Growth; the $500 base fee only earns itself back in per-message savings once volume clears 400,000. A brand sending 40,000 SMS a month sits well under the Starter-to-Growth threshold too — its $100 Growth base fee buys unlimited keywords and support, not a lower all-in rate, since 40,000 messages a month doesn’t clear the 100,000-message breakeven where Growth’s per-message saving starts covering its own base fee.

When does Postscript stop being worth the cost?

The pricing page prices the message. It has nothing to say about whether that message should have been sent, to whom, at what point in a customer’s lifecycle, and on what cadence before it starts producing opt-outs instead of revenue — and that decision, not the per-message rate, is usually where the SMS budget is actually won or lost. A brand paying Professional’s $500 base and running a short code at $750 a month is committing $1,250 before a single message goes out; whether that fixed cost is worth carrying depends on whether the flows sitting on top of it are built to convert reliably; a program with well-timed abandoned-cart messages and cadence tuned against actual unsubscribe behaviour earns that fixed cost back differently than one broadcasting every campaign to the full list regardless of recency, and the flow revenue calculator is a way to check whether your current flows are covering it.

That’s not a pricing question, it’s a system that has to be designed, watched and adjusted as sending volume and subscriber behaviour change — segmentation, send-time logic, and the discipline to stop a flow that’s producing opt-outs rather than revenue. A rising monthly bill on its own tells you nothing about whether that’s happening; rising volume alongside a falling click rate or a climbing opt-out rate is the actual signal that a flow has stopped earning the fixed cost sitting under it, and neither number lives on Postscript’s billing page. Building and maintaining that system, across SMS and email together rather than as two disconnected channels, is lifecycle flows work, and it’s the part of the Postscript bill that never shows up as a line item.