# Predictive dialer vs progressive dialer, preview and power: pacing math, abandoned-call rules and which to use

> Predictive dialers call ahead of agents to cut idle time, while progressive, power and preview dialers wait for a free agent. This guide explains how each mode works, the pacing math behind abandoned calls, the US and UK rules that limit them, and which mode fits sales, collections and support.

- Canonical URL: https://www.broadnet.me/blog/predictive-progressive-preview-power-dialer-modes-2026
- Language: en
- Last updated: 2026-11-08
- Publisher: BroadNet (https://www.broadnet.me)

- Published: 2026-11-08
- Author: BroadNet Editorial Team

**Predictive dialer vs progressive dialer** comes down to one choice: does the dialer call ahead of your agents or not? A predictive dialer calls several numbers per agent before anyone is free. It cuts idle time but can abandon calls. A progressive dialer places one call per free agent, so a person who answers should always reach an agent. Preview and power sit in between. [DialerBee](https://dialerbee.com/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026) runs all four modes, set per campaign.

> Facts checked at their sources on 8 November 2026. Legal rules come from the US Telemarketing Sales Rule and the FCC's TCPA rules (both read in the eCFR), the CFPB's Regulation F, and Ofcom's 2016 persistent misuse statement. Each one is linked inline. Facts about DialerBee come from its own website. Rules change, so check the linked source and your own counsel before you set a campaign live.

| Mode | Calls per free agent | Who starts the call | Agent idle time | Abandoned-call risk | Best fit |
|---|---|---|---|---|---|
| Preview | 1, after the agent clicks | The agent, after reading the record | Highest | None from pacing | Complex B2B sales, sensitive or high-value calls |
| Power | 1 on DialerBee (more than 1 on some products) | The dialer, as soon as wrap-up ends | Medium | None at 1 call per agent | Small and mid-size teams that want steady volume |
| Progressive | 1, released as agents free up | The dialer, ordered by priority and time zone | Medium | Very low by design | Collections, renewals, regulated lists |
| Predictive | More than 1, calculated by a model | The dialer, before agents are free | Lowest | Real; must be capped and measured | Teams of about 20+ agents on large lists |

## How does each auto-dialer mode work?

Each mode answers one question differently: when is the next number dialed, relative to when an agent is free? That timing decides agent idle time, and whether a customer can answer to silence.

- **Preview dialer.** The agent sees the contact record, notes and history first. The agent clicks to dial when ready. Nothing is dialed until a person decides. This is the slowest mode, but every call is prepared.
- **Power dialer.** The dialer places the next call automatically when the agent finishes wrap-up. On DialerBee, power mode holds one call per agent, with a wrap-up timer and options to pause, skip or reschedule ([power dialer](https://dialerbee.com/features/power-dialer/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026)).
- **Progressive dialer.** The dialer places one call for each available agent and never dials ahead of one. On DialerBee, the list is ordered by priority score, time zone and retry schedule ([progressive dialer](https://dialerbee.com/features/progressive-dialer/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026)).
- **Predictive dialer.** The dialer forecasts when agents will finish their calls. It starts dialing several numbers before they are free, so a live answer is ready the moment an agent becomes available.

Power and progressive both hold one call per agent. Power is tied to each agent's wrap-up. Progressive releases calls across the team in priority order.

> Naming trap: "power dialer" does not mean the same thing everywhere. DialerBee's [auto dialer overview](https://dialerbee.com/auto-dialer-software/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026) points out that some products use the name for 2 or 3 lines per agent, which can abandon calls. Ask every vendor how many lines per agent their power mode places.

## Predictive dialer vs progressive dialer: what is the real difference?

The real difference is who carries the risk of a bad guess. A progressive dialer waits for an agent, so the agent carries the cost as idle time. A predictive dialer guesses ahead, so when it guesses wrong the customer carries the cost as an abandoned or silent call.

Most dials do not reach a person. With progressive dialing, the agent waits through every failed attempt. If only 1 in 4 dials reaches a live person, the agent waits through about 3 failed attempts per conversation.

A predictive dialer removes that wait by dialing for the agent in advance. If the answer rate is 25%, it might start about 4 dials for each agent it expects to become free. Usually 1 of the 4 answers. Sometimes 2 answer at once. If no other agent is free, the second person hears nothing. That is an abandoned call.

| Question | Progressive | Predictive |
|---|---|---|
| Lines per agent | Exactly 1 | Variable, set by a model |
| Who waits | The agent | Sometimes the customer |
| Abandoned calls | Very rare (only if the agent is not ready) | Expected; must be capped |
| Minimum team size | Works for 1 agent | Works best with about 20+ agents |
| Setup effort | Low | Needs an abandon ceiling, limits and monitoring |
| Typical use | Collections, regulated or reputation-sensitive lists | High-volume sales or surveys on large lists |

## How does predictive pacing math work?

A predictive dialer is a queueing problem. Agents are servers and live answers are arrivals. An answer that finds no free agent becomes an abandoned call.

The table below uses the standard Erlang B formula, a simple model from telephone traffic engineering. "Pacing intensity" is the live-answer load as a share of agent capacity. These are our own illustrative calculations, not measurements. Real dialers do better because they time dials ahead, but the pattern holds.

| Agents on the campaign | Pacing intensity 70%: abandoned | Pacing intensity 70%: agent busy | Pacing intensity 85%: abandoned | Pacing intensity 85%: agent busy |
|---|---|---|---|---|
| 5 | 15.4% | 59% | 22.1% | 66% |
| 10 | 7.9% | 64% | 14.5% | 73% |
| 20 | 3.0% | 68% | 8.6% | 78% |
| 50 | 0.3% | 70% | 3.4% | 82% |
| 100 | 0.0% | 70% | 1.2% | 84% |

1. **Team size matters more than the algorithm.** At the same pacing, 100 agents abandon far fewer calls than 10. With many agents, one long call is absorbed by the others. With a few agents, one long call breaks the forecast.
2. **The last points of agent busy time are expensive.** Moving from 70% to 85% intensity adds only a few points of agent talk time. It can multiply the abandoned-call rate several times over.

This is why DialerBee recommends predictive dialing for teams of about 20 agents or more, and power or progressive for smaller teams. You can test your own numbers in DialerBee's free [abandon-rate estimator](https://dialerbee.com/tools/abandon-rate-estimator/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026), which uses the same Erlang B model.

## What are the abandoned-call rules in the US and the UK?

In the US, telemarketing calls have a 3% abandonment limit and a 2-second rule. In the UK, there is no safe 3% level since 2017: Ofcom treats abandoned and silent calls as misuse and decides cases on harm. Rules differ in every other market, so check your own.

### United States: FTC Telemarketing Sales Rule

The FTC's [Telemarketing Sales Rule, 16 CFR 310.4](https://www.ecfr.gov/current/title-16/section-310.4) says a call is "abandoned" if a person answers and the telemarketer does not connect the call to a sales representative within 2 seconds of the person's completed greeting. Abandoning calls is a violation. The rule's safe harbor protects a seller only if all of these apply:

- No more than 3% of all calls answered by a person are abandoned. This is measured per campaign, over each 30-day period or the life of a shorter campaign.
- Unanswered calls ring for at least 15 seconds or 4 rings before the dialer hangs up.
- When no representative is free within 2 seconds, the dialer promptly plays a recorded message with the seller's name and telephone number.
- The seller keeps records that prove all of the above.

The same section limits telemarketing calls to a person's home to 8:00 a.m. to 9:00 p.m. at the called person's location, unless the person has consented.

### United States: FCC TCPA rules

The FCC's TCPA rules in [47 CFR 64.1200](https://www.ecfr.gov/current/title-47/section-64.1200) set the same 3% ceiling for telemarketing calls answered live by a person, measured over 30 days per campaign. Within 2 seconds of the greeting, an abandoned call must play a short message saying the call was for "telemarketing purposes", naming the business and giving a do-not-call number. It must also offer an automated opt-out by voice or keypress.

Note the scope. The 3% rules above are written for telemarketing. US debt collection calls follow the CFPB's [Regulation F, 12 CFR 1006.14](https://www.ecfr.gov/current/title-12/section-1006.14). It presumes a collector complies if it calls a person about a debt no more than 7 times in 7 days, and not within 7 days after a phone conversation about it. Unconnected calls do not count, but an abandoned call has connected.

### United Kingdom: Ofcom persistent misuse policy

In the UK, Ofcom's [2016 persistent misuse statement](https://www.ofcom.org.uk/siteassets/resources/documents/consultations/category-1-10-weeks/7837-review-of-how-we-use-persistent-misuse-powers/summary/persistent-misuse-policy-statement.pdf?v=410974) has applied since 1 March 2017. It treats both silent calls and abandoned calls as forms of misuse. Silent calls, where the person hears nothing at all, are Ofcom's top priority. Ofcom says the 3% rate in its older 2010 policy was a way to rank cases, not a safe harbor. The 2016 statement removes any specific rate from its priority criteria. Persistent misusers can face penalties of up to £2 million.

- **Play an information message.** If no agent is free, play a brief message within 2 seconds. It should name the caller, give a basic-rate number to decline further calls, and contain no marketing.
- **Do not call back fast.** Repeat calls within 72 hours to a number that got an abandoned or silent call, without a guaranteed live agent, count as an aggravating factor.
- **Ring for at least 15 seconds.** Ofcom says shorter ringing is likely to cause more harm.
- **Measure the rate per day.** Ofcom calculates it per calendar day: abandoned calls divided by abandoned plus live calls.
- **Keep records.** Ofcom expects records for at least 6 months, and may ask for evidence of answer machine detection accuracy.

## Where does answering machine detection fit?

Answering machine detection (AMD) decides whether a person or a voicemail picked up. It affects every outbound mode, and it can create legal risk as well as save agent time.

AMD makes two errors. A **false negative** sends voicemail to an agent and wastes time. A **false positive** hangs up on a real person. Ofcom's statement names AMD as a cause of silent calls for exactly this reason. In the US, any AMD delay counts against the 2-second window that starts after the person's greeting. So the questions to ask a vendor are:

1. How does the system classify a call, and how long does it take after pickup?
2. What happens to a call classified as a person when no agent is free?
3. Can agents flag wrong classifications, and does the system learn from them?
4. Can you measure accuracy per campaign, carrier and language, and switch AMD off where the risk is too high?

DialerBee's [AI AMD](https://dialerbee.com/features/ai-amd/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026) transcribes the first seconds of audio and classifies the words, not a beep. It works in many languages, including English, Arabic, Spanish, French, Hindi and Urdu. Agents can flag errors with one click, and those corrections feed tuning scoped to your own account. DialerBee does not publish a single false-positive rate or latency figure. It says both depend on carrier, language and greeting, so ask for measurements on traffic like yours.

## Which dialer mode should you use for sales, collections and support?

Start from the team size, the list and the rules, not from the fastest mode. Most contact centers run several modes, one per campaign.

| Use case | Recommended mode | Why |
|---|---|---|
| 3 to 8 reps calling named B2B accounts | Preview | Each call needs research; volume is not the limit |
| 5 to 20 agents on inbound leads or callbacks | Power | Removes manual dialing without calling ahead |
| Collections, insurance or renewals on a regulated list | Progressive | One call per free agent; frequency and time-zone rules applied in order |
| 20+ agents on a large, low-answer-rate list | Predictive | Enough agents for the model to average out; set the abandon ceiling first |
| Inbound support teams making callbacks | Preview or power | The agent should see the open ticket before the customer answers |
| Simple reminders and confirmations at volume | AI voice agent campaign, people on callbacks | Repetitive calls do not need a person on every call |

For a deeper look at running dialers in BPOs and collections, including AI and bring-your-own-carrier economics, read our [AI outbound dialer guide for BPOs and collections](https://www.broadnet.me/blog/ai-outbound-dialer-bpo-collections-guide-2026).

## How to set up predictive dialing safely

Set the guardrails before you set the speed:

1. Confirm the consent, calling-hour, abandonment and frequency rules for every country on the list.
2. Scrub the list against your do-not-call records, and check again at the moment of dialing, not only at upload.
3. Set a maximum abandon rate per campaign below the legal limit, and a minimum and maximum number of lines per agent.
4. Record the information message, test that it plays within 2 seconds, and set ring time to at least 15 seconds.
5. Start with conservative pacing, and raise it only while the measured rate stays under your ceiling.
6. Keep pacing logs, abandon reports and AMD accuracy data for audits.

## How DialerBee does this

[DialerBee](https://dialerbee.com/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026) is the multilingual AI contact center platform from the BroadNet Group. It runs inbound queues and outbound campaigns, plus an omnichannel inbox for voice, WhatsApp, SMS and email. Its site states:

- **Four modes, chosen per campaign.** Preview, power, progressive and predictive, so a sales pod and a collections pod can each keep their own mode ([auto dialer software](https://dialerbee.com/auto-dialer-software/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026)).
- **Predictive pacing.** A machine-learning model recalculates lines per agent every 30 seconds. It uses answer rates, handle-time distributions, wrap-up times and time-of-day trends ([predictive dialer](https://dialerbee.com/features/predictive-dialer/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026)).
- **Abandon-rate ceiling.** Each predictive campaign has a hard maximum abandon rate. The model slows dialing before the ceiling is reached. Supervisors set minimum and maximum lines per agent and can pause or override pacing.
- **Simulator-gated changes.** New pacing settings are tested against historical campaign data before they go live.
- **Checks at every dial.** [Compliance Autopilot](https://dialerbee.com/features/compliance-autopilot/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026) checks the current do-not-call list, consent (with revoke), calling hours by jurisdiction and time zone, frequency limits, caller-ID ownership and phone format. Overrides are logged. Jurisdiction packs cover UAE TDRA, KSA CST, Jordan TRC and Bahrain TRA, and US calling hours follow the number's time zone.
- **Voicemail handling.** Multilingual AI AMD on the Professional plan, basic beep detection on Starter, and voicemail drop per campaign.
- **Your own carrier.** Bring your own SIP trunk, keep your PBX or SBC, or get trunks and numbers from DialerBee through sales. With your own carrier there is no per-minute platform fee ([BYOC](https://dialerbee.com/features/byoc/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026)).
- **Browser agents.** A WebRTC softphone in Chrome, Edge or Firefox, with nothing to install.

On [pricing](https://dialerbee.com/pricing/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026), Starter costs $69 per agent per month for up to 20 agents and includes preview and power dialing. Professional costs $129 per agent per month for up to 100 agents and includes all 4 modes and AI AMD. Enterprise is custom. Annual billing saves 20%. Carrier minutes are billed by your carrier. The AI voice agent is an add-on on Professional and Enterprise at $0.60 per started connected minute on managed AI.

Know the limits. DialerBee's controls are compliance-supporting; the site says it does not give legal advice or guarantee compliance. Its listed jurisdiction packs cover four Middle East regulators, so UK and US rules such as the information message are yours to configure and check. Predictive mode needs the Professional plan. The self-serve trial needs your own SIP trunk or PBX.

To see the four modes on your own list, start the [DialerBee free trial](https://dialerbee.com/trial/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026): 14 days, free AI credit, no card, connected to your own SIP trunk or PBX. If you prefer a guided session, [book a DialerBee demo](https://dialerbee.com/demo/?utm_source=broadnet.me&utm_medium=blog&utm_campaign=predictive-progressive-preview-power-dialer-modes-2026) and ask the team to run preview, power, progressive and predictive on one campaign, block a do-not-call number on purpose and show where the abandon rate is reported. DialerBee is part of the [BroadNet Group of brands](https://www.broadnet.me/brands). For carrier-grade voice routes behind any dialer, see [BroadNet voice](https://www.broadnet.me/products/voice).

## Frequently asked questions

### What is the difference between a predictive dialer and a progressive dialer?

A predictive dialer calls several numbers for each agent before any agent is free, using a forecast of when agents will finish. A progressive dialer places one call for each agent who is already free. Predictive gives agents more talk time but can abandon calls when too many people answer at once. Progressive keeps agents waiting through unanswered calls but almost never leaves a customer with no one on the line.

### What is the difference between a power dialer and a predictive dialer?

A power dialer dials the next number automatically after each call, without a person keying it in. On many platforms, including DialerBee, it places one call per agent. A predictive dialer places several calls per agent and uses a model to time them. Some products call a fixed ratio of 2 or 3 lines per agent "power dialing", and that can abandon calls, so always ask how many lines per agent a power mode uses.

### What is a preview dialer used for?

A preview dialer shows the agent the contact record, history and notes before each call, and the agent clicks to dial. It suits complex B2B sales, account management, high-value collections and sensitive conversations, where preparation matters more than volume. It is the slowest mode, but it creates no abandoned calls from pacing and gives the agent full control over each call.

### What is the legal abandoned call rate?

In the US, the FTC Telemarketing Sales Rule and the FCC's TCPA rules set a 3% limit for telemarketing calls answered by a person, measured per campaign over 30 days, with a recorded message within 2 seconds. In the UK, Ofcom's 2016 policy sets no safe rate: abandoned and silent calls are misuse, and Ofcom acts based on harm. Other countries set their own rules, so check each market.

### Does a progressive dialer ever abandon calls?

It should not abandon calls because of pacing, since it dials one number for each free agent. A call can still go wrong if the agent is not actually ready, if the agent hangs up on a live person, or if answering machine detection wrongly classifies a person as a machine. Ofcom treats silent calls from these causes as misuse too, so progressive mode still needs good processes and monitoring.

### How many agents do you need for a predictive dialer?

Most guidance, including DialerBee's, points to about 20 agents or more. With a small team, one long call breaks the forecast, which causes either idle agents or abandoned calls. In a simple Erlang B model at the same pacing, 10 agents abandon several times more calls than 50. Smaller teams usually get better results from power or progressive mode.

### Does answering machine detection cause abandoned calls?

It can. When AMD wrongly classifies a live person as a machine and hangs up, the person experiences a silent call, which Ofcom names as a form of misuse. In the US, the 2-second limit starts after the person's greeting, so slow detection can push a call past it. Measure AMD accuracy per campaign and switch it off where the risk is too high.

### Which dialer mode is best for debt collection?

Progressive is usually the safest default for collections because it places one call per free agent and keeps calls in priority and time-zone order. Preview suits complex or high-balance accounts. In the US, Regulation F presumes compliance at no more than 7 calls in 7 days per debt, so frequency limits matter as much as the dialing mode.