Connect rate vs conversation rate: two different problems
Telemarketers often conflate these two metrics, but they measure completely different things. Connect rate is the proportion of dials that result in someone picking up the phone, whether that is a receptionist, a personal assistant, or the target contact. Conversation rate (sometimes called decision-maker reach rate) is the proportion of dials that produce a qualifying conversation with the specific person you intended to call.
Connect rate is a data quality metric. If a number is disconnected, routes to an out-of-service tone, or rings out with no answer after multiple attempts, that is a data problem. Conversation rate, by contrast, is partly a caller skill metric and partly a targeting metric: you might connect every time but still fail to get through gatekeepers, or you might reach the right person but have a weak opening that ends the call in ten seconds.
This distinction matters for diagnosis. A team returning a 4% connect rate on a supposedly fresh file is not a team that needs retraining. They need better data. A team with a 14% connect rate but a 2% conversation rate probably has a gatekeeper problem or a script problem. Fix the right thing.
B2B vs B2C benchmarks: what should you expect?
The table below reflects realistic ranges on UK telemarketing files across different data types. These assume a competent calling operation, correct call times, and suppression applied at the point of supply.
| Data type | Typical connect rate | Key limiting factor | Freshness threshold |
|---|---|---|---|
| B2B direct-dial (landline DDI) | 12-18% | Job mobility; number reassignment after staff changes | 12 months |
| B2B switchboard / main number | 8-13% | Gatekeeper blocking; no direct route to contact | 18 months (numbers more stable, but contacts change) |
| B2B mobile (direct to decision-maker) | 15-22% | Faster decay when contact changes employer or role | 6-9 months |
| B2C consumer landline (TPS-suppressed) | 9-15% | Landline adoption declining; TPS registration rate rising | 18 months |
| B2C consumer mobile (TPS-suppressed) | 11-17% | Number porting; SIM changes; high TPS registration among 45+ cohort | 12 months |
| Aged or unverified file (any type) | 2-6% | Accumulated disconnects, reassignments, and TPS additions | Beyond threshold |
These ranges assume the numbers have been verified at the stated freshness threshold. A B2B file described as "updated 18 months ago" should be treated as an aged file, regardless of what the supplier calls it.
Why direct-dial numbers change everything
The single biggest lever on B2B connect rate is whether you have a direct-dial number (DDI) for the individual contact, rather than the company's main switchboard number. A switchboard call requires a gatekeeper to transfer you, which introduces a refusal point before you have said a word about your product. DDI numbers route straight to the person's desk phone or direct mobile, removing that barrier.
A Manchester-based IT reseller running a campaign to target IT Directors in professional services firms once found its connect rate jumped from 9% to 16% simply by switching from a switchboard-only file to one with DDI numbers appended. The script and the callers were identical. The data was the variable.
For more on what makes a B2B direct-dial file reliable, see our guide to B2B direct-dial numbers in the UK.
Switchboard numbers still have a place
Do not write off switchboard numbers entirely. For targeting very senior contacts (C-suite or board level) where direct-dial numbers are genuinely scarce, a well-structured switchboard approach can still work. The difference is that you need a stronger opening sequence and more experienced callers to handle gatekeepers effectively. The data quality issue is less about connect rate and more about whether the contact is still at that organisation.
How data freshness affects your dial-list
UK B2B job mobility is the main enemy of telephone data quality. Roughly 20-25% of decision-maker direct-dial numbers in any given B2B file become unreliable within a year, as individuals change roles, move employers, or have their DDI reassigned after they leave. A file that was accurate when compiled in May 2025 will have shed a meaningful proportion of its working numbers by May 2026, even without any errors in the original compilation.
For B2C consumer files, the decay pattern is different. Consumer mobile numbers are more persistent than B2B direct-dials (people keep personal mobiles even when switching jobs), but TPS registrations accumulate over time. A consumer number that was not TPS-registered 18 months ago may well be registered now, which means calling it becomes a Privacy and Electronic Communications Regulations (PECR) breach. This is why the suppression wash must happen at the point of data supply, not once during onboarding and never again.
Our guide to B2B data decay and refresh covers the full picture on how quickly different data types degrade and when to trigger a refresh cycle.
The freshness window by data type
As a working rule: B2B direct-dial data should be no more than 12 months old at the point of calling. B2B switchboard numbers are more stable and can extend to 18 months, though the contact attached to that number may have moved on. B2C consumer telephone data should be refreshed within 18 months, with TPS re-washed immediately before any campaign regardless of when the file was compiled.
The 12-month B2B threshold is not arbitrary. Companies House filings show that UK SMEs turn over roughly a quarter of their senior staff annually. For a list of 5,000 B2B contacts compiled 14 months ago, you should expect perhaps 1,000-1,200 of those direct-dial numbers to have issues before you even start dialling.
TPS, CTPS, and suppression: the legal floor and the practical impact
The Telephone Preference Service (TPS) is the UK opt-out register for consumer telephone marketing. Calling a TPS-registered number for direct marketing purposes without prior consent is a breach of PECR and can result in Information Commissioner's Office (ICO) enforcement action, including fines. The Corporate Telephone Preference Service (CTPS) extends the same protection to sole traders and partnerships (but not limited companies).
For a full breakdown of how TPS, MPS, and CTPS interact and who they apply to, see our article on TPS, MPS, and CTPS explained.
In practical terms, TPS suppression on a consumer file typically removes 18-30% of records from a raw list. That feels like a loss, but these records are ones you cannot legally call. Removing them before campaign launch is not just compliance; it is a genuine improvement to your working dial-list because it concentrates your calling time on numbers that are legally available.
PECR reminder
TPS suppression must be applied no more than 28 days before the campaign start date. A suppression wash performed three months prior is legally insufficient: new TPS registrations will have accrued in the gap. Reputable data suppliers apply TPS as part of order fulfilment, not at point of compilation months earlier.
Mobile data quality in B2B: higher reach, faster decay
Business mobile numbers are the most effective type of B2B telephone data for direct contact with a decision-maker. They bypass the switchboard entirely, they are answered at more hours of the day, and they reach the individual rather than the role. Connect rates on verified B2B mobiles routinely run 15-22%, versus 12-18% on direct-dial desk numbers.
The trade-off is decay speed. A business mobile is tied to a person, not a desk. When that person leaves their employer, the mobile number does not get reassigned to their replacement in the way a DDI sometimes does; it either becomes inactive or moves with the individual to their new role (where the old company association is now wrong). For this reason, B2B mobile numbers in a file should be treated as reliable only within a six-to-nine-month window from verification.
In our experience, campaigns that mix verified DDI landlines (for stability) with verified business mobiles (for reach) consistently outperform files that rely on one type alone. The landlines provide a fallback when the mobile is unavailable; the mobiles provide direct access when gatekeepers are a barrier.
How to validate data quality before a campaign
Never take a supplier's word for freshness. Before committing to a full campaign dial-list, ask for a sample of 100-200 records and run a test dial session across two or three calling days at different times. Track four numbers separately:
- Live connects: someone answered.
- Disconnected / not in service: the number is dead.
- Unanswered / voicemail: the number exists but no contact was made.
- Switchboard barrier: connected but could not reach the named contact.
A disconnected rate above 10% on a supposedly fresh sample is a clear warning sign. A sample that is described as 6 months old should have a disconnected rate below 5%. If those numbers do not hold, push back on the supplier before ordering the full file.
Also ask directly: when was TPS suppression last applied, and is it applied at point of fulfilment rather than at point of compilation? Any supplier that cannot answer both questions clearly is a supplier worth avoiding.
When to call: time-of-day effects on connect rate
Data quality determines the ceiling on your connect rate. Calling times determine how close you get to that ceiling on any given day.
For B2B, the most productive windows are Tuesday to Thursday, 08:45-11:30 and 14:00-17:00. Monday mornings are lost to catch-up emails and internal meetings. Friday afternoons produce low intent even when you do connect. Lunchtime dials (12:00-13:30) tend to reach PAs covering desks rather than the decision-makers themselves.
For B2C, the picture shifts. Consumer landlines produce their best connect rates between 18:00-20:30 on weekdays, when people are home. Weekend mornings (10:00-12:00) also perform well for homeowner-focused products. Calling during daytime weekday hours on consumer landlines is increasingly futile as fewer people are at home to answer.
A B2B file with a genuine 14% connect rate potential will often return only 7-8% if callers work exclusively 09:00-17:00 Monday to Friday without adjusting for those dead windows. The data has not changed; the calling pattern is leaving half the value on the table.