Volume

Volume pricing uses the same bands as tiered pricing, but it picks one rate for the whole quantity. It finds the band the total quantity lands in, then charges every unit at that band's rate. Buying more can lower the price of everything you bought.

Use it when you want a clean "the more you buy, the cheaper each unit" story, where crossing a threshold discounts the entire order.

Worked example

Same three bands as the tiered example:

Band	Rate per unit
1 to 50	$10.00
51 to 150	$8.00
151 and up	$6.00

A customer makes 100 calls. 100 lands in the second band, so all 100 units are priced at $8.00:

100 units x $8.00 = $800.00

Tiered pricing charged $900.00 for the same 100 units, because it kept the first 50 at $10.00. Volume reprices the whole quantity at the landing band, so it comes out lower here. That gap is the whole point: volume rewards crossing a threshold, tiered does not.

Settings

Same band fields as tiered pricing:

Field	What it does
Up to	The band's upper limit. Leave the last band empty for "and up".
Unit amount	The price per unit when the total quantity lands in this band.
From	The lower bound, shown for display.

Edge cases

• One rate for the whole quantity. Only the landing band's rate is used. The other bands never apply to part of the order.
• The price can drop as quantity rises. Crossing into a cheaper band reprices every unit, so a larger order can cost less in total than a smaller one near a boundary. Check your bands if that is not what you want.
• The last band must be open. Leave its upper limit empty.

In the API

{
  "pricing_model": "volume",
  "pricing_config": {
    "tiers": [
      { "tier_from": 0,   "tier_to": 50,   "unit_amount": 1000 },
      { "tier_from": 51,  "tier_to": 150,  "unit_amount": 800 },
      { "tier_from": 151, "tier_to": null, "unit_amount": 600 }
    ]
  },
  "currency": "USD"
}