EnrollHere's outbound dialing uses pools of phone numbers (DIDs) so you're not hammering the same number on every call. This article explains the 25-DID purchase cap, how pools rotate, and when to request more numbers.
When to Use This
Read this if:
You're trying to buy more than 25 DIDs at once and seeing "Maximum of 25 numbers per purchase reached."
You're setting up a new campaign and want to understand how many DIDs you need.
Numbers in your pool are getting flagged and you want to know how rotation handles it.
The 25-DID Purchase Cap
You can claim up to 25 numbers per purchase. When you reach 25 selected in the purchase flow, the remaining checkboxes (and the Select All button) are disabled and you'll see "Maximum of 25 numbers per purchase reached."
Why the cap exists: to protect agencies from accidental large purchases.
If you need more than 25: simply run multiple purchases back-to-back. There's no agency-wide cap, only a per-purchase one.
What Number Pools Do
A number pool is a set of DIDs the dialer rotates through when placing outbound calls. Instead of every outbound coming from one number, the dialer cycles through the pool so:
No single DID accumulates the call volume that would trip carrier spam models.
If one DID gets flagged, it's only a fraction of your volume — not all of it.
Local-presence routing can match the area code of the called party.
How Rotation Works
When the dialer places an outbound call, it picks a DID from the pool. Selection considers:
Volume balancing — DIDs with lower recent volume are preferred.
Area-code matching — DIDs matching the recipient's area code are preferred.
Health — DIDs flagged or in a cool-down rotate out of active use.
How Many Numbers Should I Have?
There's no perfect formula, but a rough guide:
1 agent doing 50–100 dials/day: 5–10 DIDs.
5-agent team, 500+ dials/day: 25–50 DIDs.
20+ agent enterprise: 100+ DIDs, often segmented by campaign or region.
The principle: spread per-DID volume thin. The thinner the volume per number, the less likely carriers flag any one of them.
Pool Warmup
A brand-new DID typically performs best after a short "warmup" period — a few days of moderate, non-spammy outbound activity. Throwing 500 dials/day at a 24-hour-old number is the fastest way to get it flagged.
📌 Pair pool expansion with our spam-removal scrub service so newly added numbers are registered immediately. See the Spam Flagging article for details.
Common Pitfalls
Treating the pool as static. Agencies that grow need to grow pools; static pools age and degrade.
Skipping caller-ID registration. A new pool without scrubbing is a pool ready to be flagged.
📌 Tip
If you're scaling fast, claim numbers in batches over multiple days rather than all at once. It gives carriers and our scrub service time to register each batch, and reduces the chance of a brand-new pool getting hit with spam labels day one.