App Stack Cost

Aisles / Email and SMS / Postscript

Postscript review and real cost

SMS and RCS marketing for Shopify with per-message pricing and built-in list growth tools.

Good, with caveats5/8 checks passed#3 of 4 in email and smsBy Postscript4.7 from 1,208 App Store reviews

Verdict

A strong pick for US stores that want SMS as its own channel, with published per-message rates and no profile fees. The catch is that Starter's $49 monthly minimum and carrier fees apply even to small senders, and some merchants struggle to reach a human for support.

Install it if

  • US stores that run SMS separately from their email tool
  • Stores that want to pay per text with no profile fees
  • Klaviyo, Gorgias or Privy users adding SMS

Skip it if

  • Stores that want email and SMS in one tool (email is on a waitlist)
  • Merchants who need fast human support on the entry plan
  • Brands that require a finished SOC 2 report

Good

  • Per-message rates and average carrier fees are published, so bills are easy to predict2.
  • 30-day free trial with a $100 sending credit2.
  • Rated 4.7 from 1,208 reviews, with 95% five-star ratings1.
  • No profile fees, so a bigger list doesn't raise the base price2.

Not so good

  • Starter has a $49 monthly minimum after the trial2,3.
  • Carrier fees are billed on top of message fees2.
  • Live chat and email support start on Growth at $100 a month2.
  • SOC 2 is listed as in progress, not complete6.
Postscript
Monthly bill by store size
  • 300 orders$57
    Starter
  • 2,000 orders$197
    Starter
  • 10,000 orders$984
    Starter

Message volume and carrier fees drive the bill; Growth's $100 fee only pays for itself above 100,000 texts a month2,4.

Public prices, billed monthly, checked October 8, 2026.

The eight checks

Postscript passes 5: good, with caveats. What each check means.

  • Free to start: passedFree trial with a $100 credit for the first 30 days2.
  • Prices public at every size: passedPlan fees, per-message rates and average US carrier fees are published2.
  • Built for Shopify: failedThe listing does not show the Built for Shopify badge1.
  • Rated 4.7 or higher: passedRated 4.7 on the Shopify App Store1.
  • 500+ merchant reviews: passed1,208 reviews on the Shopify App Store1.
  • Works with Shopify Flow: failedShopify Flow is not listed under Works with1.
  • You can take your data: passedPostscript's help centre shows how to download a segment's subscribers as a CSV file on every plan5.
  • Security report named: failedPostscript's trust centre lists SOC 2 as in progress6.

Pricing

PlanPriceIncludesLimits
Starter$0/month + usage; $49 monthly minimum1,2Campaigns and automations, unlimited segments, toll-free number, 2 opt-in keywords, list growth tools; $0.009/SMS, $0.045/MMS$49 monthly minimum spend; carrier fees extra
Growth$100/month + usage1,2Starter plus unlimited opt-in keywords, live chat and email support; $0.008/SMS, $0.03/MMSCarrier fees extra
Professional$500/month + usage1,2Growth plus priority support, enhanced analytics, API access, no Postscript branding on opt-in; $0.007/SMS, $0.024/MMSCarrier fees extra
EnterpriseContact us2Professional plus a dedicated Customer Success Manager, custom product recommendations, data warehouse pushCustom pricing
Postscript AI Plan$699/month + usage2Brand Center, Infinity Testing and Shopper AI productsPer-message rates of $0.003 to $0.30 depending on product and message type

You pay per message. Starter has no platform fee but a $49 monthly minimum and charges $0.009 per SMS; Growth costs $100 a month at $0.008; Professional costs $500 at $0.0072. Carrier fees are passed through at cost on their own line, averaging $0.0033 per US SMS, and each 160-character segment counts as one SMS2. Postscript's per-carrier table lists $0.0035 to $0.0050 per outbound US SMS, so the real carrier charge can run a little above that average4. Using the published average, Starter is the cheapest choice at all three of our store sizes, at about $57, $197 and $984 a month. Growth only pays off above 100,000 texts a month.

Usage charges: Starter $0.009/SMS and $0.045/MMS; Growth $0.008 and $0.03; Professional $0.007 and $0.024; plus carrier fees passed through at cost, averaging $0.0033 per US SMS2. A dedicated short code costs $750 a month in carrier fees2.. Free trial: 30 days with a $100 sending credit2.

How we worked out the bill

Store sizePer monthArithmetic
Small, 300 orders$572,400 SMS x $0.009 = $21.60, below the $49 monthly minimum, so $49 + carrier fees 2,400 x $0.0033 = $7.92 on their own line = $56.922,3
Growing, 2,000 orders$19716,000 SMS x $0.009 = $144 + carrier fees 16,000 x $0.0033 = $52.80 = $196.80; Growth would be $100 + $128 + $52.80 = $280.802
Large, 10,000 orders$98480,000 SMS x $0.009 = $720 + carrier fees 80,000 x $0.0033 = $264 = $984; Growth would be $100 + $640 + $264 = $1,0042

What it does

Postscript is an SMS marketing app for Shopify that runs campaigns, automations and segments from your store data1. It includes list-growth tools such as Onsite Opt-in, popups and checkout collection, plus a dedicated toll-free number2. RCS is available, and email is on a waitlist2.

It works with Klaviyo, Gorgias, Privy and Zapier1. AI products such as Brand Center, Infinity Testing and Shopper come in a separate AI plan at $699 a month2.

  • Campaigns, automations and unlimited segments built on Shopify data1,2.
  • Onsite Opt-in, popups, checkout collection and keywords to grow the SMS list2.
  • A dedicated toll-free number, verified for you at no charge2.
  • RCS messages from a branded profile2.
  • AI products (Brand Center, Infinity Testing, Shopper) in a separate $699-a-month AI plan2.
  • Built-in compliance guardrails for TCPA and carrier rules2.

What merchants say

Postscript is rated 4.7 from 1,208 reviews, with 95% five-star ratings1. Merchants praise fast setup, cart-recovery and welcome flows, compliance features and revenue within weeks1. Recent low ratings mention AI-only answers to tricky support questions, billing and contract disputes, and editor glitches7.

Complaints worth knowing

  • Recent reviews say it is hard to reach a human when the AI support can't solve an issue7.
  • Some merchants report charges they didn't expect and a yearly contract that renewed before they could leave7.
  • One merchant reports glitches and edits that don't save in the message and popup builder7.

What the developer claims

Numbers the developer publishes about itself. We have not verified them.

  • Onsite Opt-in captures up to 3x more subscribers2.
  • 20-30% lower email pricing than legacy providers, for an email product that is still on a waitlist2.
  • The most competitive SMS rates2.

Your data

You can download any segment's subscribers as a CSV file on every plan5. Postscript's trust centre lists CCPA and GDPR as compliant and SOC 2 as in progress6. It does not say there where data is stored6.

App languages: English. Works with: Checkout, Customer accounts, Shopify Admin, Gorgias, Klaviyo, Privy, Sumo, Zapier. On the App Store since: September 26, 2018.

Other email and SMS apps

AppChecks300 orders2,000 orders10,000 orders
Klaviyo
7/8 checks passed$105$570$2,275
Omnisend
6/8 checks passed$95$515$2,034
Attentive
4/8 checks passedQuoteQuoteQuote

Sources

  1. Postscript SMS Marketing - Shopify App Store, Shopify App Store. Accessed October 8, 2026.
  2. Postscript pricing, Postscript. Accessed October 8, 2026.
  3. Understanding Your Usage Bill, Postscript Help Center. Accessed October 8, 2026.
  4. Understanding Carrier Fees, Postscript Help Center. Accessed October 8, 2026.
  5. View Subscribers Included in a Segment, Postscript Help Center. Accessed October 8, 2026.
  6. Postscript Trust Center, Postscript. Accessed October 8, 2026.
  7. Postscript SMS Marketing reviews (1-2 stars, newest), Shopify App Store. Accessed October 8, 2026.

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