What a capability is
A capability is a per-number flag that decides which traffic that number can carry. It is set by the carrier that issued the number and by the regulations of the country it belongs to. You do not turn capabilities on inside Finn. You choose a number that already has them at purchase time, in Settings → Phone numbers → Rent a number, where you pick a country, see the numbers available there, and can tick Show only SMS-capable numbers.
| Capability | What it does |
|---|---|
| Voice (inbound) | Receive calls placed to this number. |
| Voice (outbound) | Place calls from this number, presented as caller ID. |
| SMS | Send SMS. Needed for SMS steps in sequences. |
Not every number supports every capability, and the combination varies by country and by number type. Assume nothing about a number you have not checked. The phone numbers list shows the capabilities of each number in your inventory alongside its country, assigned Finn, and monthly cost.
Number types and what they change
Local numbers are the default and are priced per country.
Renting a number is refused until your workspace has an approved compliance application. Settings → Compliance lists your applications and their status (Submitted, Approved, Rejected), and for businesses registered in India collects the Certificate of Incorporation and GST Certificate. See phone-numbers for the purchase path and byo-numbers for bringing your own numbers.
Capabilities are not the whole story for outbound
A number with outbound voice can still fail to complete calls. Capability answers whether the network will accept traffic from the number. It says nothing about how receiving carriers treat it: a number they label as spam keeps dialing, but answer rates collapse. See spam-labeling.
Finn does not register numbers with carriers. What it does give you is the Health column in Settings → Phone numbers: a rolling 7-day score built from connect rate, short-call ratio, and failure rate against your workspace baseline (Healthy, Watch, At risk; it needs 30+ calls in the window). From a number's health drawer you can pause, isolate, or rotate it before it drags a campaign down.
Capacity is separate from capability
A single number that supports outbound voice cannot carry thousands of simultaneous calls. That is a capacity limit, not a capability limit, and no setting removes it. For parallel deployments, group numbers into a pool and assign the pool instead of a single from-number. Each number in a pool carries at most 5 concurrent calls. See number-pools and concurrency.
What to check when something fails
| Symptom | Likely cause |
|---|---|
| Answer rates collapse on one number | Carriers may be labeling it as spam. Check its Health score and see spam-labeling. |
| Inbound calls aren't answered by a Finn | The number has no live inbound deployment. There are no business-hours rules: a number answers whenever its inbound deployment is running. See inbound-routing. |
Releasing changes capability permanently
Removing a number (Settings → Phone numbers → row menu → Remove number) releases it back to the carrier and stops inbound calls to it immediately. A number attached to an active deployment cannot be removed; Force remove stops that deployment first. Released numbers usually cannot be recovered, and Finn doesn't port numbers out. If a number is critical, keep it rather than releasing it.