> ## Documentation Index
> Fetch the complete documentation index at: https://docs.synctera.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Balance Floor and Ceiling and Linked Accounts

> Accounts can have a minimum and maximum balance, referred to as the balance floor and balance ceiling. These attributes can be used to implement a number of features, including pool accounts.

Balance Floor and Ceiling can be set while creating an account using [`POST /v0/accounts`](/v2/reference/createaccount)

## Balance Floor

An account's balance floor consists of two attributes:

* `balance`: the minimum balance the account can have
* `linked_account_id`: the ID of the linked account used to maintain the minimum balance

The balance floor creates a lower limit for the available balance of that account. Any transaction that would put the available balance of the account below its balance floor triggers a just-in-time (JIT) funding transaction from the linked account in order to bring the balance back up to the floor.

## Balance Ceiling

The balance ceiling creates an upper limit for the available balance. Any transaction that would put the available balance of the account above its balance ceiling triggers a just-in-time (JIT) funding transaction (also known as a sweep transaction) to the linked account in order to bring the balance back down to the ceiling.

## Example Use Cases

### Pool Account

There are a number of use cases where you want an account that always has a zero balance, and gets its funds from another account. For example, you many have a single pool account containing the funds for multiple business expense cards. In this case, each card's account would be set up like:

<CodeGroup>
  ```json JSON theme={"system"}
  balance_floor: {
      "balance": 0,
      "linked_account_id": "{POOL_ACCOUNT_ID}"
  }
  balance_ceiling: {
      "balance": 0,
      "linked_account_id": "{POOL_ACCOUNT_ID}"
  }
  ```
</CodeGroup>

All credits and debits to any of the card accounts would flow through to the pool account. Refer to the [Business Expense Cards](/v2/docs/business-card) for more details.