Most agencies I talk to have figured out SMS rebilling. They buy segments at one rate, add a markup, pass it to the client as a line item, and keep the spread. Fine. It works. But the same agencies hand their clients an outbound calling tool (or worse, let the client buy one themselves) and don't rebill a single minute of it. That's margin sitting on the floor.
Full disclosure: I work for Ready, and we ship a Power Dialer alongside the SMS platform. So I have a reason to want you selling both. But the model below works with any dialer that bills per minute and doesn't charge you per seat. The math is the math.
Why minutes are easier to mark up than segments
SMS rebilling has an awkward property: clients can count messages. They sent 5,000 texts, they expect roughly 5,000 charges, and when the invoice says 8,200 segments because someone dropped an emoji into the template, you get a reconciliation fight at renewal. Segments are a unit the client half-understands, which makes them a unit the client half-audits.
Minutes are different. Nobody on the client side is counting dial seconds. They care about one thing: did the calls book appointments or close deals? That makes per-minute pricing a cleaner place to hold a markup, there's no "I sent 22,000 but got billed for 38,000" surprise. A minute is a minute.
The catch is that your margin on minutes evaporates if your agents sit idle, because you're paying for connected time and your client is paying you for value, not raw dial time. More on that below, the utilization math is the thing that actually decides whether this works.
The cost side: what you actually pay per minute
Ready's Power Dialer is billed per agent, with minutes in 6-second increments. Three tiers:
| Plan | Per agent/mo | Minutes | Per-minute after |
|---|---|---|---|
| Free | $0 | 1 agent, 500 min included | $0.06/min |
| Pro | $29 | up to 3 agents | $0.05/min |
| Team | $69 | unlimited agents | $0.0375/min |
No per-seat fee on the platform itself, the per-agent figure is the dialer cost, and it comes with CRM, pipeline, unified inbox, and the SMS side with no additional seat charges. That matters because a chunk of agency margin usually dies in per-seat CRM fees before a single text goes out.
Take the Team tier at $0.0375/min. That's your floor cost for connected minutes. Round it to $0.045 to bake in a little buffer for setup time, voicemail drops, and the odd long call, and now you've got a clean internal cost number to mark up from.
The rebill side: $0.10 a minute is defensible
Here's the spread. You pay ~$0.045 all-in (Team-tier minutes plus a buffer). You bill the client $0.10. That's a 2.2x markup and $0.055 of gross margin per minute.
Is $0.10/min defensible to a client? Compare it to what they'd pay a standalone dialer product or a contact-center seat license, and $0.10 looks cheap. Compare it to what an appointment-setting agency charges per booked call, and it looks free. The client isn't buying minutes, they're buying "someone dials my leads in the first five minutes and books them." The minute is just the meter.
Worked example. A client's sales team runs 3 agents, 4 hours of dial time a day, 20 working days. Say agents are connected (talk + ring + voicemail) about 35% of dial time, that's a realistic utilization number for a decent cold list:
- 3 agents × 4 hrs × 20 days = 240 agent-hours/mo
- 35% connected = 84 connected hours = 5,040 billable minutes
At your cost: 5,040 × $0.045 = $226.80 (plus the agent fees, more below). At your rebill: 5,040 × $0.10 = $504.00. Gross spread on minutes alone: $277.20/mo.
That's not life-changing. The blend is where it gets interesting.
The blended model: seat + minutes + SMS
Don't sell minutes as a lone line item. Agencies that split texting and calling into two separate charges leave money on the table and give the client two things to question. Bundle it.
Say you package an "outbound" retainer for that same 3-agent client:
1. Seat / platform fee. Your dialer cost is 3 agents on Team = 3 × $69 = $207/mo. Bill a flat platform access fee that covers it with margin, call it $450/mo for "outbound dialer access + management." Spread: $243/mo.
2. Minutes. From above: $277.20/mo spread.
3. SMS. Pair every dial with a text, a pre-call "we'll be reaching out" and a post-call "missed you, here's a link." Say the client sends 12,000 segments/mo. Your cost on Ready Standard is $0.02 + $0.0045 carrier = $0.0245/seg = $294. Rebill at $0.05/seg = $600. Spread: $306/mo. (And if volume climbs past 50,000 segments in a month, your per-segment cost drops automatically to $0.016 and the spread widens without you touching the client's rate.)
Stack it:
| Line | Your cost | Rebill | Spread |
|---|---|---|---|
| Platform (3 seats) | $207 | $450 | $243 |
| 5,040 minutes | $227 | $504 | $277 |
| 12,000 SMS segments | $294 | $600 | $306 |
| Total | $728 | $1,554 | $826/mo |
$826/mo of blended margin from one client, on a bundle that reads as a single "outbound engine" retainer. That's $9,912/year per client, and the client sees one number against one outcome: pipeline.
The utilization trap that eats the minute margin
I keep flagging this because it's where the model quietly breaks. Your minute margin assumes agents are dialing. If you sold a 3-seat platform fee and your client's reps only actually dial two days a week, you're still paying $207 in agent fees against far fewer billable minutes, and your effective margin collapses.
Two defenses:
- Price the platform fee to cover seats regardless of usage. The $450 flat covers the $207 even if nobody dials. The minute spread becomes pure upside on top.
- Watch for false economy on call screening. Answering-machine detection feels like it saves minutes, but AMD hangs up on roughly 1 in 8 live humans, fewer billed minutes, yes, but also fewer booked deals, which is the thing your retainer is actually sold on.
Don't skip the compliance line
Before you rebill a single dial, scrub the list. Known TCPA-litigators and DNC-complainers belong off the dial list, and Ready's standalone scrub runs $0.005 per contact, on a 10,000-record list that's $50 to document your diligence. When a client's bad list sparks a complaint, the scrub trail is what keeps your agency's name off it. Build the $0.005 into your onboarding fee, not your margin.
And half a cold list is often landlines you can't legally text anyway, so a line-type scrub before DNC keeps your SMS rebill honest too, you're not billing segments to numbers that'll never deliver.
The practical takeaway
If you already rebill SMS, you have the muscle to rebill minutes, you're just metering a second unit against the same client, through the same platform, with no new per-seat fee to absorb. The move is:
- Use a per-minute dialer with no separate seat tax (Team tier = $0.0375/min, unlimited agents).
- Set an internal cost floor with a buffer (~$0.045/min).
- Rebill minutes at a round, outcome-justified number ($0.10).
- Wrap it with a platform fee that covers seats and an SMS line, so the client buys one outbound engine.
- Scrub first, and price utilization risk into the flat fee, not the minute spread.
That turns a tool you were giving away into roughly $800+/mo of blended margin per client, most of it from a line item your competitors haven't thought to add yet.
If you want to run your own numbers, the Power Dialer tiers and SMS pricing are all public, and you can start with 20 free texts and a free dialer seat before you quote a client anything. Build the bundle on paper first. The margin either clears the utilization math or it doesn't, better to know before you pitch it.