# Price logics

Price logics are rules added to plans to charge subscribed customers. A plan can have multiple price logics.

There are 5 types available to choose.

## Flat Fee

This is a simple flat fee for every subscribed customer. It doesn't depends on usage and it can be charged at the beginning of each period or at the end.

## Per Unit

This adds same price for each unit of a meter.

Example:
You set a per unit price logic with a value of \$2. If your customer has 25 uses in the period, the price logic will add \$50 to the final price.

## Stair Step

With this price logic, you can set Tiers to determine the amount charged. The price of each tier applies to any usage within the tier limits.

Example:
You set a Stait Step price logic with the following tiers:
`0 - 100 = \$50`
`101 - inf = \$150`

If your customer has 70 uses in the period, the price logic will add \$50 to the final price. If usage is above 101, the price logic will add \$150 to the final price.

## Tiered

With this price logic you can define a per unit price that changes acording to different Tiers.

Example:
You set a Tiered price logic with the following tiers:
`0 - 100 = \$3`
`101 - 500 = \$2`
`501 - inf = \$1`

70 uses => `70 * \$3 = \$210`
210 uses => `100 * \$3 + 110 * 2 = \$520`
600 uses => `100 * \$3 + 400* 2 + 100 * 1 = 1200`

## Volume

With this price logic you can set the same per unit price based on tiers.

Example:
You set a Volume price logic with the following tiers:
`0 - 100 = \$3`
`101 - 500 = \$2`
`501 - inf = \$1`

70 uses => `70 * \$3 = \$210`
210 uses => `210 * \$2 = \$420`
600 uses => `600 * \$1 = \$600`