How to Audit Your DIDs: The 10-Minute Self-Check Every Agency Should Run
A simple weekly routine to catch flagged, mis-registered, or drifting DIDs before they tank your contact rate. No special tools required.
TL;DR
A 10-minute weekly self-audit catches flagged, mis-registered, and drifting DIDs before they tank your contact rate. The routine: pull your active number list, spot-check five CNAM dips against LIDB, test-call from three mobile networks, run a reputation lookup against Hiya Inc., Transaction Network Services (TNS), and First Orion, and scan for idle or un-owned numbers. No special tools required.
Most agencies discover their DIDs are flagged the same way: a producer complains that nobody is answering, and by the time the problem surfaces in metrics, a week or more of dialing has been wasted. A basic weekly audit catches drift early — it takes 10 minutes and requires nothing more than a phone, a spreadsheet, and a couple of free lookup tools. Here is the routine.
Why this matters even if you have a monitoring tool
Monitoring tools are good at detecting changes against a baseline. But they only know what you tell them, and they only check what you configured. A self-audit catches three categories of problem that automated tools miss:
- DIDs that were added to your PBX but never registered with your monitoring stack
- CNAM drift — the display your VoIP vendor thinks is set vs. what actually dips
- Numbers that were released or ported without your knowing
The cost of missing these is not hypothetical. Hiya's Q2 2025 report flagged 13.7 billion suspected spam calls globally (Hiya Global Call Threat Report); if you are on the wrong side of that signal for even a week, producer pickup rates collapse. A weekly 10-minute self-check is a compliance backstop, not a replacement for continuous monitoring. Combined with a tool like LineAudit, it covers the gaps.
The 10-minute routine
Minute 0-2: Pull the list
Export the active DID list from your PBX or SIP trunk provider. You need:
- DID (full E.164 format)
- Assigned agent or team
- Assigned CNAM (as configured on your end)
- Date added to the pool
- Last-used date or rolling 7-day call volume
If your PBX cannot export this, that is problem number one. You cannot audit what you cannot list.
Minute 2-4: Spot-check CNAM dips
Pick 5 random DIDs from the list. For each, run a CNAM dip — most wholesale trunk providers offer a lookup tool, and several free services exist. Compare the dip result against what your PBX thinks it is set to.
Expected result: exact match. Common failure modes:
| Discrepancy | Meaning |
|---|---|
| Dip returns "UNKNOWN" | LIDB record was never populated |
| Dip returns prior owner's name | LIDB propagation failed on port-in |
| Dip returns truncated or abbreviated form | Carrier LIDB cache is stale |
| Dip returns different CNAM than expected | Multiple systems are writing to LIDB |
If even one of the five spot-checks shows a discrepancy, extrapolate: you probably have 15-20% mismatch across the pool. Escalate to your trunk provider to run a full LIDB refresh.
Minute 4-6: Test-call from three mobile carriers
Keep three test phones — one on each of the major mobile networks — and call them from three DIDs you have not tested this month. You are looking at:
- Does the call ring through, or does it go straight to voicemail?
- What displays on screen? CNAM? Number only? "Spam Likely" label?
- Is there any pre-ring delay suggesting analytics intervention?
Record results in your audit spreadsheet. Over a month you will have tested 12 DIDs across 3 carriers — a reasonable sample from a 50-100 DID pool. The test-call routine catches labels faster than any monitoring service because the label surfaces exactly where it matters: on the consumer handset. Independent industry data indicates 87% of consumers ignore calls from unknown numbers even when they are expecting them (First Orion INFORM overview), so what displays on the handset is effectively the whole game.
Minute 6-8: Reputation lookup
Use the Free Caller Registry lookup (joint intake for Hiya, TNS, and First Orion per their joint launch announcement) or run the free LineAudit check against the first 20 DIDs in your pool. Both will return:
- Flagged / not flagged
- Associated business (if registered)
- Carrier-level reputation indicators
Flag any DID that comes back "flagged" in any category for immediate review.
Minute 8-10: Activity and ownership check
Two final quick checks:
- Activity: Any DID in the pool with zero calls in the last 14 days. Idle DIDs accrue risk (ports get hijacked, LIDB records drift, carriers reclaim disused numbers). Either use them or release them.
- Ownership: Cross-reference your DID list against your trunk provider's current billing. Any mismatch means either you are paying for numbers you do not have, or you have numbers that were released without your knowledge. Both are problems.
Cross-check your list against the FCC Reassigned Numbers Database (RND) operated by Somos Inc. when onboarding new DIDs — it is the one federally-sanctioned safe-harbor mechanism against TCPA exposure on recycled numbers.
Weekly audit scorecard
Keep results in a running sheet. A reasonable scorecard:
| Metric | Green | Yellow | Red |
|---|---|---|---|
| CNAM mismatch rate | <5% | 5-15% | >15% |
| Flagged DIDs (Spam/Scam) | 0 | 1-3% | >3% |
| B or C attestation DIDs | 0 | any | >5% |
| Idle DIDs (14+ days) | <10% | 10-25% | >25% |
| LIDB dip "UNKNOWN" rate | 0 | 1-5% | >5% |
Any row in red triggers escalation to your trunk provider or remediation workflow. Any row in yellow for two consecutive weeks is also actionable.
Escalation workflow
When the audit flags something, the response depends on what broke:
| Finding | Immediate action | Longer-term fix |
|---|---|---|
| CNAM mismatch | Submit LIDB correction to trunk provider | Set up monthly LIDB audit |
| Spam Likely label | Pause outbound, start remediation | Review dialing pattern that triggered it |
| Scam Likely label | Remove from rotation | Likely replace — scam labels rarely remediate fast |
| B or C attestation | Escalate to trunk provider, cite 47 CFR § 64.6301 | Consider switching providers if recurring |
| Idle DID | Either rotate into use or release | Right-size the pool |
| Ownership mismatch | Contact trunk provider billing | Audit procurement process |
What a good self-audit cadence looks like
- Weekly: Spot-check 5 DIDs via the routine above. Total time: 10 minutes.
- Monthly: Full-pool reputation check via LineAudit or equivalent. Total time: 20-30 minutes depending on pool size.
- Quarterly: Full LIDB reconciliation with your trunk provider. Total time: 1-2 hours including follow-up.
- On port-in: Verify CNAM and attestation within 48 hours of port-in completion. A new DID's first week is when most issues surface.
Common mistakes
Auditing only after a producer complains. By then the damage is measurable in lost dials. An agent posting to a peer community captured the pattern plainly: "Pickup rate is trending down. Had a prospect tell me I was coming up as spam on his phone" (Insurance Forums, "Need help: Number getting flagged as spam"). By the time a prospect is telling you, your analytics verdict is already weeks old.
Trusting the PBX display. Your PBX shows what it was configured to send. It does not show what the terminating carrier actually displays. These diverge more often than most agency owners realize.
Over-indexing on one carrier. A DID that is clean on one mobile network can be flagged on another. Test-calls need to span all three major networks.
Auditing only the production DIDs. The DIDs you rotated out but still own still carry reputation risk and can be ported out from under you. Audit the full inventory, not just active rotation.
Not documenting the audit. A written trail of weekly audits is useful evidence if you ever need to escalate a reputation dispute. "We have clean audit logs showing no abusive behavior" moves disputes faster than any other argument.
FAQ
Q: Do I need a separate tool for CNAM dips? A: Most wholesale SIP trunk providers include a CNAM lookup in their portal. If yours does not, several free lookup tools exist, or use the LineAudit free check.
Q: What if I have 500+ DIDs? A: Sample-based weekly audits are still fine — you are looking for drift, not full coverage every week. Monthly full-pool scans fill the gap.
Q: Can I automate the test-calls? A: Partially. Automated test-calls from cloud numbers can detect call-through and basic analytics behavior, but they cannot see the display on an actual consumer handset. Manual test-calls from real phones remain the gold standard.
Q: How do I know which agent each DID is assigned to if my PBX does not track it? A: This is a bigger problem than the audit itself. Fix the assignment tracking first. You cannot do accountability or branding strategy without knowing who owns which number.
Q: Should agents do their own audits? A: Agents should test-call their own numbers weekly to a personal mobile on a different carrier. It is a 30-second check and it catches issues before they reach list-wide metrics.
Q: Is this audit redundant if I already use a reputation monitor? A: No — it covers gaps the monitor does not see (PBX-configuration drift, idle inventory, ownership/billing mismatch). Combine both.
Q: What is the single most valuable check? A: Test-calling from real consumer handsets across all three major mobile networks. Everything else is a proxy; the handset is the source of truth.
Q: How does the FCC Reassigned Numbers Database fit into my audit? A: On inbound port-ins and new provisioning, check each number via the RND. It establishes TCPA safe-harbor and catches numbers whose prior owner behavior may already have seeded a negative reputation.
Q: How often do LIDB records drift once they are set correctly? A: Rarely if left alone, but ports, provider migrations, and cache invalidations all cause periodic drift. A monthly dip spot-check is sufficient steady-state.
Q: What tooling do small agencies actually use day-to-day? A: A spreadsheet plus wholesale-provider portal plus a monitoring service. The 10-minute routine is intentionally tool-agnostic because most agencies do not need anything more.
The bottom line
Ten minutes a week prevents weeks of wasted dials. Most agency reputation disasters are slow-motion — drift, staleness, unnoticed labels — and are completely catchable with a disciplined self-audit.
Related: spam-label remediation and DID rotation strategy.
Stop guessing. Run the audit.
LineAudit checks your first 20 DIDs free. You'll see exactly which numbers are flagged, mis-registered, or at risk — in 30 seconds.