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

# Create or Update Account Number

> Use this endpoint to set the full account number, routing number, transit numbers, and banking institution for an account as needed.

## Path Parameters

<ParamField path="user_id" type="String" required />

<ParamField path="member_id" type="String" required />

<ParamField path="account_id" type="String" required />

## Body Parameters

<ParamField body="account_number" type="string">
  The full, unmasked banking account number associated with a particular account.
</ParamField>

<ParamField body="institution_number" type="string">
  Must be three-digit number to identify a Canadian banking institution.
</ParamField>

<ParamField body="routing_number" type="string" required>
  Must be valid nine-digit routing number.
</ParamField>

<ParamField body="transit_number" type="string">
  Must be three-digit number to identify a Canadian banking institution.
</ParamField>