> ## Documentation Index
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# RatePlanTier Subobject

The `RatePlanTier` object describes a single Tier of a `RatePlan`, including its price, whether to charge by individual Unit or by stepped Tier Price, and the lower limit of the Tier.

| Value | Data Type | Description |
| - | - | - |
| `name` | string | **Required.** The descriptive name for the Tier. |
| `ratePrice` | `RatePlanPrice` | **Required.** An array of `RatePlanPrice` objects, which define the Price (or prices) for this Tier (one price for each currency used). The `RatePlanPrice` object is an (amount, currency) pair, which contains two data members: - `amount`: the number of currency units. - `currency`: the ISO 4217 currency code to be used for this `ratePrice`. |
| `chargeCustomer` | `ChargeCustomer` | An object of type `ChargeCustomer`, which may be one of two types: - `FlatFee`: charges the customer a defined price per Tier. - `PerUnit`: charges the customer a defined price per Rated Unit. `FlatFee` defines a stepped pricing structure, in which the customer is charged the `ratePrice` per Tier. `PerUnit` defines a graduated pricing structure, in which the customer is charged the number of units accessed, multiplied by the `ratePrice` per Tier. |
| `beginsAtLevel` | decimal | The number of Units at which this Tier’s pricing structure takes effect. The number of Units defined for each Tier runs from the minimum value of the Tier, to one `Unit` less than the minimum value of the next higher Tier. Typically the first tier would have `beginsAtLevel` = 1. The final, highest tier is unbounded (infinite). |
| **Parent topic:**[RatePlan Subobjects](../topics/RatePlan_Subobjects) | | |


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