What is VoIP termination billing?
VoIP termination billing is how carriers charge for outbound calls that leave your network and complete on the public switched telephone network. For BPOs, call centers, and VoIP resellers, the billing model directly shapes cost per connected call, campaign ROI, and how you route traffic. The most transparent method is per-second billing, where you pay only for the exact duration of a completed call.
The building blocks of a termination bill
Before looking at per-second billing, it helps to understand the common factors that make up an outbound termination charge:
- Rate per minute: The advertised price for a destination. In the US and Canada this is typically by NPA-NXX or by country code for international.
- Billing increment: The granularity used to count time. Common increments are 1/1 (per-second), 6/6, or 60/60.
- Minimum chargeable time: Some carriers set a first minimum, such as 6 seconds, even if the increment is 1 second after that.
- When billing starts: Charges begin only after answer supervision is signaled. Attempts, ring-no-answer, and busy are not billable.
- Rounding method: Each increment is rounded up. With 60/60, a 61-second call bills as 120 seconds. With 1/1, 61 seconds bills as 61 seconds.
- Connect or setup fees: Less common in wholesale US termination, but if present they apply per completed call.
- Surcharges: Some routes include extras for special destinations or features. Review your rate deck for any such notes.
How per-second billing works
Per-second, often shown as 1/1, means there is no 30-second or 60-second rounding. Your cost is your exact connected seconds multiplied by the per-minute rate, divided by 60.
Example: If the rate is $0.005 per minute and the call lasts 23 seconds, the charge is 23 × 0.005 ÷ 60 = $0.0019167. On a 60/60 plan, that same 23-second call would bill as 60 seconds, or $0.005.
Two additional notes:
- Minimums: Some carriers combine 1/1 with a small minimum, such as 6 seconds. In that case, a 2-second connected call bills as 6 seconds, then per second after that.
- Partial seconds: Billing systems typically round the call duration to the nearest whole second for calculation. Sub-second fractions are not billed.
Why per-second matters for call centers and resellers
Per-second billing maps closely to real talk time. That matters when you run predictive or preview dialers, outbound collections, or B2B appointment setting:
- Short calls and agent transfers: High volumes of sub-60-second connects add up. Per-second billing avoids paying for unused time blocks.
- Retry logic and time-of-day windows: Campaigns that rely on frequent short engagements see more accurate cost alignment with outcomes.
- Wholesale pass-through: Resellers who need to price competitively can quote transparent per-second terms to their own customers.
What you do and do not pay for
In wholesale VoIP termination, you are charged only for answered calls. You do not pay for ring-no-answer, busy, failed attempts, or calls that never receive answer supervision.
Once a call is answered, the clock runs until one side hangs up or the network releases the call. That total connected time is what is billed, using the applicable increment and rounding rules.
Reading your CDRs to verify billing
Your Call Detail Records are the source of truth. To self-audit:
- Match answer and release time: Duration should equal release time minus answer time. Check for timezone consistency.
- Confirm billing increment: Recalculate a sample using 1/1 math. If you see 60-second blocks on short calls, the account may be on 60/60.
- Check minimums: If many 1, 5 second calls all bill as 6 seconds, a 6-second minimum is in effect.
- Validate answer supervision: Ensure your platform properly detects and signals answer to avoid false connects.
- Look for surcharges: Some destinations may carry special rates. Your rate deck notes should match the CDR effective rate.
Common billing increments explained
- 1/1 (per-second): Best for accuracy and savings on short calls. Preferred by high-volume dialers.
- 6/6: Rounds to the next 6 seconds. Middle ground for some networks.
- 60/60: Rounds to the next minute. Simpler but costly for short-duration traffic.
Even a small change in increment can affect effective cost. If your average connected call is 28 seconds, moving from 60/60 to 1/1 can materially lower your spend without changing your answer rate.
How rates and routing affect your final bill
Billing is not only about increments. Rate selection and routing strategy also drive cost and quality:
- Destination granularity: US and Canada rates by NPA-NXX are more precise than country-level. Mismatches can lead to out-of-deck charges.
- Quality tiers: Direct or premium routes may cost more but improve answer supervision and reduce false connects, which protects your billing accuracy.
- LCR policy: Least-cost routing should respect quality thresholds. Chasing the lowest rate can increase short calls and retries that erase savings.
Operational tips to keep per-second costs tight
- Tune call progress detection: Accurate AMD and answer detection prevents billing for machine connects you meant to drop.
- Control post-dial delay: Long PDD hurts agent experience and can inflate abandon rates. Choose routes with stable signaling.
- Hang up cleanly: Ensure your system releases calls promptly when an agent or callee disconnects, so billing stops at the right moment.
- Monitor short-duration ratios: Excessive sub-6-second connects may indicate routing or compliance issues that increase effective cost.
- Audit often: Recalculate a random CDR sample monthly to confirm per-second behavior aligns with your agreement.
How TalkTelX handles VoIP termination billing
TalkTelX is a US-registered VoIP carrier, FCC RMD-listed and STI-PA authorized. We provide US and Canada outbound termination with prepaid, per-second billing, plus inbound origination and US DIDs, local and toll-free, for carriers, wholesalers, and call center operators.
What you can expect:
- Per-second outbound termination: 1/1 billing to align charges with real talk time.
- Transparent CDRs and rate decks: Clear pricing and consistent reporting for straightforward reconciliation.
- Compliance-focused routing: STIR/SHAKEN signed where applicable to support call completion and reputation.
Bottom line
Per-second VoIP termination billing gives you precise cost alignment with the way your agents and dialers actually talk. Understand your increments, verify with CDRs, and pair accurate billing with quality routing to keep your effective cost per connect under control.
Ready to move your outbound to per-second billing or review your current setup? Contact TalkTelX to discuss routes, rate decks, and a quick test on your traffic.