Post Account Updates

Allows a partner to push different types of account updates to Flex. This is a web hook endpoint that accepts many different types of updates. Processing of the updates is done out of band.

note

This endpoint is hosted by Flex. If you are a multi biller partner, you must use the endpoint with both biller and account params, if you are a single biller partner, you should use the endpoint with just an account parameter.

Endpoint

POST /sbi/account/:accountId

Base URL: https://partner-bridge.{env}.getflex.com

Idempotency

This endpoint enforces Idempotency by the payloads update_id and the Partner’s Client Id. When a duplicate update is provided it will be ignored, even if the content of the update is different from previous versions. The HTTP code will still be 202 Accepted.

Request

Headers

Header	Type	Required	Description
X-Client-Id	string	Yes	Your client ID (provided by Flex)
X-Api-Key	string	Yes	Your API key (provided by Flex)
Content-Type	string	Yes	Must be application/json
Idempotency-Key	string	Yes

Request Params

Param	Required	Description
account_id	yes	The account id in the partner’s system

Request Body

{
  "update_id": "9d936acb-25dc-49c4-b01e-022c0f5c68aa",
  "type": "RefundIssued",
  "data": {
    "amount_in_cents": 10000,
    "refund_date": "2026-01-01",
    "refund_id": "44e94edc-f3f8-46ed-9f07-1bafa200f708",
    "reason": "A reason to refund"
  }
}

Field	Type	Required	Description
update_id	string	true	The unique id for this update from the Partner. This plus the Partner’s client id are the Idempotency Key.
type	enum<RefundIssued, PriceAdjustment, AccountCancellation>	true	The type of update the Partner is communicating to Flex about this account.
data	RefundIssued, PriceAdjustment, AccountCancellation, BalanceUpdate	true	The details about the update depending on the update type
reason	String	false	A human readable reason for the refund.

RefundIssued

A RefundIssued event should be sent to Flex whenever funds previously sent by Flex to the biller are being sent back to Flex. This is money Flex will need to credit or refund to the customer.

Field	Type	Required	Description
amount_in_cents	int	true	The amount of money that is being refunded to the account and Flex will receive back from the Biller
refund_date	yyyy-mm-dd	true	The date the funds were sent back to Flex.
refund_id	String	yes	The id of the refund in the partner’s system.

PriceAdjustment

A PriceAdjustment event should be sent to Flex whenever a paid bill has had its price adjusted. This will allow Flex to ensure it is well setup to underwrite the customer for future bills as well as disperse new funds to the biller if needed.

This event will not trigger a refund to the customer as that is handled by the RefundIssued event.

Field	Type	Required	Description
old_amount_in_cents	Integer	true	The amount before the adjustment to the account
new_amount_in_cents	Integer	true	The amount after the adjustment to the account

AccountCancellation

An AccountCancellation event should be sent to Flex when the customer's account with the biller is canceled. This will enable Flex to correctly reflect the account status to the customer. Flex can also get this information by pulling the Get Account endpoint.

Field	Type	Required	Description
effective_date	String, YYYY-MM-DD	true	The date at which the cancellation will take effect

Response

Success (202 ACCEPTED)

{
  "message": "Request accepted."
}

Response Fields

Field	Type	Description
message	String	A human readable description of the result

Error Responses

404 Not Found

Returned when the client ID is not recognized or the account cannot be found.

{
  "code": "NOT_FOUND",
  "message": "Resource not found"
}

500 Internal Server Error

Returned when an unexpected error occurs on the Flex side.

{
  "code": "INTERNAL_ERROR",
  "message": "An unexpected error occurred"
}