# Top up an MMF investment wallet from a business wallet

> 🔒 **Private label — [contact sales](mailto:sales@boyahq.com).** Requires a private-label entitlement on your API client.

Top up an MMF investment wallet from a business wallet

Endpoint: POST /investments/accounts/{fundAccountId}/top-up
Version: 2.0.0
Security: oauth2ClientCredentials

## Path parameters:

  - `fundAccountId` (string, required)

## Header parameters:

  - `Idempotency-Key` (string)
    Required on write endpoints (POST). UUID per submission. Middleware dedupes for 24h.

  - `org_wallet_ref` (string)

  - `business_id` (string, required)

## Request fields (application/json):

  - `source_wallet_id` (string, required)
    Business wallet to debit
    Example: W123456

  - `amount` (number, required)
    Example: 10000

  - `currency` (string, required)
    Example: KES

  - `reference` (string, required)
    Example: MMF-TOPUP-...