Auto-scaling automatically adds numbers to a RingPool as traffic grows and removes unused numbers at the end of each billing cycle.
Promo numbers are a limited and valuable resource, which is why most Invoca accounts automatically manage the quantity of numbers in a RingPool through auto-scaling. Auto-scaling can both add numbers to improve call attribution and remove numbers automatically so you’re not billed for ones you don’t use.
When a landing page receives enough visitors quickly enough to use up all the promo numbers in a RingPool, two things happen:
- Instead of a unique promo number, a visitor sees a different number based on your settings — either an overflow number (which still tracks and routes the call, but without personalized attribution) or the original destination number (with no tracking or attribution at all).
- If enabled, auto-scaling automatically adds more promo numbers to the RingPool, which are shown to subsequent visitors instead of the overflow number — even if a visitor never actually calls that number.
Auto-scaling also removes unused numbers automatically: at the end of each month, it removes unused promo numbers from your RingPool before your next billing cycle begins.
Enabling auto-scaling in your account
Auto-scaling is enabled for most accounts, including all new ones. To check whether your RingPools have it enabled, contact your Invoca Account Manager, or have a Super User follow these steps:
- Log in to Invoca. In the sidebar menu, click Settings.
- In the Network section, if you see RingPool Auto-Scaling, it’s enabled for your account. Click it to edit your settings.
- From there, you can enable auto-scaling for each new RingPool you create, and choose whether those RingPools include an overflow number.
If you don’t see the Auto-Scaling option and want it enabled, reach out to your account team or submit a support request.
FAQs
Why am I still receiving overflow calls if my RingPools are increasing automatically?
By default, auto-scaling adds only one new promo number every five minutes. During a sudden traffic surge, it may take several minutes for your RingPool to reach the right size.
Why are my RingPools increasing if I didn’t receive any overflow calls?
Auto-scaling triggers whenever an overflow number is presented on your landing page, whether or not it’s actually called — this maximizes the number of visitors assigned unique promo numbers.
Does auto-scaling work with local phone numbers?
Yes. For a local number RingPool, auto-scaling tries to grow with a number from the same location first, falling back to a toll-free number if none are available locally.
Can I enable auto-scaling only for some campaigns?
Yes — the same settings menu described above lets you apply auto-scaling to only certain campaigns or destination numbers.
How does auto-scaling remove unused promo numbers?
Each night, auto-scaling marks the least recently called numbers in an eligible RingPool as “Reserved” — held as standby capacity rather than removed immediately (see What Is a Reserved RingPool Number?). On the last day of each month, auto-scaling checks those Reserved numbers and removes any that still qualify as unused, so you aren’t billed the following month. A number is considered unused if it hasn’t been shown to a visitor in the past 5 days or received a call in the past 10 days. If a RingPool has shown an overflow number in the past 30 days, it doesn’t scale down at all. Auto-scaling never removes more than 20% of a RingPool’s numbers in a single month.Last modified on October 9, 2026
