0) and may use numbered subaccounts 1–63.
Subaccounts are currently an API-only feature — they are not yet supported in the
Kalshi web or mobile app. Numbered-subaccount balances and positions are managed through
the trade API.
Numbering
Transfers
You can move cash between your own subaccounts withPOST /portfolio/subaccounts/transfer (amounts in cents). Transfers net to
zero at the account level — nothing leaves your account.
Transfers are idempotent on a client-supplied client_transfer_id: retrying
with the same value returns 409 instead of applying the transfer twice.
Listing transfers
GET /portfolio/subaccounts/transfers returns your subaccount transfers,
paginated.
Restricted API keys
When generating an API key you can restrict it to a single subaccount. A restricted key can only read and trade on that subaccount: order placement and management, portfolio reads (balance, positions, fills, settlements), order groups, and the full REST RFQ lifecycle — creating combo markets in multivariate event collections, creating and cancelling RFQs, posting, confirming, and cancelling quotes, and accepting quotes. Requests that omitsubaccount act on the key’s locked subaccount, and naming any other
subaccount is rejected.
A restricted key cannot transfer funds, manage subaccounts or API keys, or
act on RFQs and quotes belonging to a different subaccount of the same
account. Subaccount-scoped requests match rows created through the API with
an explicit subaccount identity; RFQs created in the web app are not
addressable per subaccount. Endpoints outside its allowed set return
403 this API key is restricted to a single sub-account and cannot access this endpoint. On FIX, restricted keys support order entry and the maker
quote lifecycle only — RFQ creation (35=R) and quote acceptance (35=UA) are
not available to restricted FIX sessions.