Call volume is rarely flat. A product launch, a billing cycle, or a service incident can double inbound traffic for a fortnight and then return to normal. Moving up a tier for that fortnight is the wrong shape of solution.
A Voice Minutes Pack adds 10,000 conversation minutes to your account as a one-off purchase. Packs are consumed only after the minutes included with your subscription are exhausted, they never expire, and they stack — so buying two now and using them across four months is entirely reasonable.
Nothing about your configuration changes. Concurrency, languages, voices and routing stay exactly as they are; you are only buying headroom on volume.
