How to purchase and manage DIDs at scale
Bulk porting, aging policy, spam scoring, CNAM. The boring stuff that burns bad carriers.
Don't trust public number searches
A vendor with a live number-search UI is telling you their inventory is scraped before you get near it. Bots hit those endpoints constantly, and the freshly released numbers — the ones with a 30-day history of hang-ups from collections and political calls — are the ones that rank high in the search results because they look "available." By the time you pick one, it's already on a Hiya watchlist and your first campaign tanks. Ask every vendor for their aging policy in writing. Ours is 90 days post-release before a number re-enters allocation, and every number gets a spam-score check at provisioning — Hiya, First Orion, TNS, and YouMail. A vendor who can't articulate an aging policy doesn't have one, and you'll inherit numbers that were burning two weeks ago. The extra question takes thirty seconds. The cost of a bad DID pool is months of suppressed answer rates.
Bulk porting done right
Port in batches of 50–200 numbers per LOA, not one giant spreadsheet. Batched LOAs move faster at the losing carrier's provisioning desk and let you stage the migration over 2–4 weeks instead of holding your breath for a single cutover. Confirm the FOC (Firm Order Commitment) date in writing before you sign anything; the LOA without a FOC is the paperwork equivalent of an IOU. FCC rules give the losing carrier four business days to release US/CA local and ten business days for toll-free — a losing carrier that asks for longer is stalling, and you can escalate to the NANPA or the FCC directly if they miss. Keep the losing trunk alive during the cutover window so traffic for pending numbers doesn't drop; the winning carrier should route the ported numbers by the FOC timestamp down to the minute. Porting fees are close to zero-cost on the carrier side — if you're being charged per-number, you're being upsold.
CNAM matters more than you think
Caller ID Name is the 15-character field your callee's phone actually displays when your call rings. If the field is stale, empty, or shows "SPAM LIKELY" because your OCN isn't whitelisted in the terminating carrier's CNAM database, answer rates drop 30–50% in measurable A/B tests. CNAM is a pull-model on most US mobile networks: the terminating carrier dips a CNAM database when the call arrives, using your OCN and TN as the key. Keep your CNAM registration current per number and update it whenever you change calling purpose (outbound sales → inbound support). Register with all four major CNAM sources — Neustar, Syniverse, Transaction Network Services, and iconectiv — so the dip succeeds regardless of which carrier is terminating. The registration itself is free or near-free; the operational work is keeping it in sync when you rotate numbers across campaigns.
Spam score hygiene
Four analytics firms score every US number continuously: First Orion (Verizon), TNS (AT&T), Hiya (T-Mobile and Samsung devices), and YouMail. A bad campaign — high hang-up rate in the first 3 seconds, high complaint rate, short call durations — can drop a number's score to the point where it's labeled "Scam Likely" across all four networks within 48 hours. Once that happens, the number is functionally dead for 3–6 weeks regardless of what you change about your dialing behavior. Rotate numbers before they hit the burn threshold (we retire at a TNS score of 70, down from a baseline of 95), enforce a minimum inter-call gap of 60 seconds from the same number to the same destination, and monitor the scores daily via the respective analytics APIs. If a number's score drops, retire it permanently — the temptation to "warm it back up" with friendly traffic almost never works and distorts your metrics while you try.
Porting out (if you ever have to)
The easiest way to evaluate a carrier you haven't bought from yet is to ask, in writing, what the porting-out process looks like. A carrier who makes it hard is telling you the relationship is a one-way door, and you'll discover that the hard way in eighteen months when you need to leave. The good version: LOA template available in the customer portal without a support ticket, FOC response within 48 business hours, no exit fees, no minimum-notice clauses, and a named person on their side who owns the port. The bad version: LOAs that require a phone call, "processing fees" of $5–15 per number, 30–60 day notice clauses buried in the MSA, and silent FOC delays that stretch the migration into an operational crisis. We've seen every bad pattern in this industry. The port-out process should look identical to the port-in process — because the carrier on the other side of the LOA is about to be in exactly the position you're in now.
Clean DIDs. No scraped inventory.
Pick your country and NPA on /dids — we'll price the batch and ship clean aged numbers after KYC.