White label SMS marketing means a partner builds and runs a client's text program on Klaviyo SMS, Postscript or Attentive while your agency sells it under its own name. Message costs are small: Postscript lists $0.007 to $0.009 per SMS plus carrier fees. The risk is compliance. TCPA damages run $500 to $1,500 per message.
Most results for this keyword are about reselling SMS software under your logo. They skip the agency version: selling SMS as a managed service on platforms your clients already use. They also say little about consent, opt-outs or quiet hours. This guide covers all three, using FCC, CTIA, Klaviyo and Postscript sources. It is not legal advice. Have a lawyer review each client's program.
What does white label SMS marketing include?
Split the work into what a partner can run and what your agency must own.
| Task |
Outsource to a partner? |
Why |
| Flow builds (welcome, cart, browse, post-purchase) |
Yes |
Repeatable production work |
| Campaign copy and scheduling |
Yes, with your approval |
Volume work with clear briefs |
| Opt-in forms and disclosure text |
Partner drafts, you approve |
Errors here create legal exposure |
| Quiet hours and sending settings |
Partner configures, you verify |
One wrong setting affects every send |
| Offer calendar and segmentation strategy |
Keep in-house |
Ties to the client's margins and goals |
| Legal sign-off on consent language |
Client's counsel |
Neither you nor the partner should own this |
| Reporting and client calls |
Keep in-house |
The relationship is the product |
The pattern matches email. Partners handle production. Your team handles judgment calls and anything that carries legal risk. Our white label Klaviyo guide covers the email side of the same retention scope.
What are the SMS compliance basics an agency must know?
Five areas cause most problems: consent, disclosure, opt-outs, quiet hours and damages.
Consent. The FCC's consumer guide says written or oral consent is required for all autodialed or prerecorded calls or texts to a wireless number, and written consent for telemarketing. CTIA's Messaging Principles say senders should get express written consent to receive marketing messages specifically.
Klaviyo's consent guide adds practical rules. SMS consent must be collected separately from other channels. It cannot be a condition of purchase, or look like one. Double opt-in is a US carrier requirement for any cart abandonment flow.
Disclosure. Postscript's compliance checklist lists what every opt-in needs: consent to automated marketing texts, message frequency, "Message and data rates may apply," HELP and STOP instructions, and links to SMS terms and a privacy policy. Checkout checkboxes cannot be pre-checked.
How do opt-outs and quiet hours work?
Opt-outs. The FCC's revocation of consent rule took effect April 11, 2025. Per Klaviyo's summary, brands must honor opt-outs made by any reasonable means within 10 business days. REVOKE and OPT OUT joined STOP, QUIT, END, CANCEL and UNSUBSCRIBE as keywords. One confirmation text within 5 minutes is allowed if it has no marketing content. CTIA's principles say no further messages after that confirmation.
Quiet hours. The TCPA window is 8am to 9pm in the recipient's local time, per Postscript's quiet hours guide. Several states are stricter:
| Where |
Sending window |
Source |
| Federal (TCPA) |
8am to 9pm local |
Postscript |
| Florida, Connecticut, Maryland, Oklahoma, Washington |
8am to 8pm local |
Postscript |
| Texas |
9am to 9pm Mon to Sat, noon to 9pm Sun |
Postscript |
| Pennsylvania |
No sends on Sundays and listed public holidays |
Klaviyo |
Postscript's own safe recommendation is 9am to 8pm local. Texas enforcement in Postscript is opt-in, so someone has to switch it on. In Klaviyo, the conservative Eastern time setting limits Texas flow texts to 11am to 8pm ET Monday to Saturday.
Damages. Postscript's compliance FAQ puts TCPA exposure at $500 to $1,500 per message. On a 50,000-person send, small errors get expensive fast.
Klaviyo SMS, Postscript or Attentive: which should your agency resell?
Resell what the client already runs. Migrating platforms adds risk and slows the first send.
Klaviyo SMS fits clients already on Klaviyo email. One profile, one flow builder, shared segments. Klaviyo's credit guide shows a US SMS uses 1 credit and a US MMS uses 3 under legacy credit pricing. An SMS holds 160 characters, or 70 with an emoji or special character. Split messages drop to 153 characters per segment.
Postscript publishes its rates. The pricing page lists Starter at $0 a month with a $49 minimum and $0.009 per SMS, Growth at $100 a month and $0.008, and Professional at $500 a month and $0.007. US carrier fees add $0.0033 per SMS and $0.00799 per MMS.
Attentive does not list per-message rates on any public page we found. Get a quote per client before you price the service.
For the partner, the skill set is similar across all three: flows, segments, copy within character limits, and compliance settings.
How much does white label SMS marketing cost?
There are two cost lines: messages and labor.
Messages. Take a client on Postscript Growth sending 100,000 SMS a month. That is $100 for the plan, $800 in messages at $0.008, and $330 in carrier fees at $0.0033. Total: $1,230 a month before MMS. One retention cost guide estimates $1,000 to $1,500 a month in messaging for 100,000 texts, which lines up.
Labor. Freelance Klaviyo specialists run $40 to $150 an hour on Fiverr, with basic flows at $150 to $400 each. A dedicated pod is the other model. Sorted's pods start at $21,600 per specialist per year, against $110,000+ all-in for a US hire.
Message costs should pass through to the client, either billed directly by the platform or invoiced at cost. Do not absorb them into a flat fee. Volume swings in Q4 will wreck the margin.
How should you price SMS to your clients?
Charge a management fee for the work and pass through platform costs. A worked example with illustrative inputs:
A 12-person Klaviyo agency in Denver adds SMS to an email retainer. It pays a partner $800 a month for four campaigns and flow upkeep. It charges the client $1,600 a month for SMS management. Message costs bill to the client's own Postscript account.
Gross margin is $800, or 50%, before internal time. Add two hours of review and client reporting at a $60 loaded hourly cost and margin is $680, or 43%. Price at $1,800 and margin after review is $880, or 49%.
Two rules keep this healthy. Scope a fixed number of campaigns per month. And charge separately for new flow builds. Our white label marketing pricing guide walks through the same markup math for other services, and Klaviyo agency pricing shows what brands pay for retention retainers.
What does an SMS partner need from your agency?
Give the partner the minimum access that lets them work, and keep the rest.
- Platform seats. A Klaviyo or Postscript user under your agency, with permissions limited to the accounts they run.
- The consent record. Where each client's subscribers opted in, the disclosure text used, and the date it changed.
- Brand voice rules. Tone, banned words, emoji policy, and how discount codes are written.
- Offer calendar. Sale dates, launches and blackout days, at least a month ahead.
- Approval path. Who signs off copy, links and send times, and by when.
- Escalation contact. One person at your agency for a wrong send or an angry reply.
Write these into one onboarding doc per client. A partner who has it on day one ships the first flow faster and makes fewer compliance mistakes. Sorted staffs pods in about two weeks, and this doc is what lets the work start on time.
How do you vet an SMS partner on compliance?
Ask questions with checkable answers:
- Show us an opt-in form you built, with its disclosure text.
- Which quiet hours settings do you use in Klaviyo, and do you enable Texas rules in Postscript?
- How do you handle inbound replies that ask to stop without using a keyword?
- Who approves campaign copy before it is scheduled?
- What happens if a send goes out during quiet hours?
A good partner answers from their own process, with screenshots. Our guide on how to choose a white label agency has the full vetting list, and the white label agency agreement guide covers who carries liability in the contract.
When is white label SMS the wrong choice?
No consent foundation. If a client's list came from purchased data or unclear sources, no partner can make it compliant. Fix consent first.
Very small lists. A client with 1,500 SMS subscribers may not justify a separate monthly fee. Bundle a few flows into the email retainer instead.
No review step. SMS goes out instantly and cannot be recalled. If nobody at your agency checks copy, links and send times, do not outsource. Build the review layer first.
More on these trade-offs in when not to offshore agency work. The white label playbook shows how SMS fits with the other services you can resell.
