Omnibus Account Management

This example shows how to implement omnibus account patterns in Formance using a declarative ledger schema. An omnibus account is a pooled account held at a financial institution that aggregates assets belonging to multiple end-users — the assets represent liabilities to your clients.

Common use cases:

• Banking services holding pooled client funds in a single settlement account
• Financial markets managing custodial accounts on behalf of investors
• Crypto platforms with fiat reserve management across banking partners

The Complete Schema#

This is the full ledger schema for an omnibus account system. The sections below explain each part.

Chart of Accounts#

The chart section defines three account groups using standard correspondent banking terminology. Nostro ("ours") accounts represent assets you hold at partner institutions. Vostro ("yours") accounts represent liabilities — funds clients hold with you.

Banks (Nostro Accounts)#

These are normal debit accounts — they represent your assets held at partner banks. The $bank_id is typically an IBAN (FR7630004028379876543210943) or routing:account format (021000089:123456789).

The payout sub-accounts isolate each withdrawal as a separate staging area, so you can track the lifecycle of each payout independently.

Clients (Vostro Accounts)#

Normal credit accounts — they represent your liabilities to clients. The credit balance shows funds you owe them.

Platform#

Mixed nature accounts — operational accounts for suspense handling, revenue, and costs. Suspense accounts are normal debit (assets awaiting attribution); revenue and cost accounts follow standard income statement conventions.

Transaction Patterns#

Client Deposit#

The CLIENT_DEPOSIT transaction records an identified deposit. The allowing unbounded overdraft clause on the bank account permits it to go negative — this accommodates the common case where ledger entries are recorded before bank statement reconciliation.

#![feature("experimental-account-interpolation")]
vars {
  asset $asset
  number $amount
  account $bank_id
  account $client_id
  string $reference
}
send [$asset $amount] (
  source = @banks:$bank_id:main allowing unbounded overdraft
  destination = @clients:$client_id:main
)
set_tx_meta("reference", $reference)

Unidentified Deposit#

When funds arrive but you can't identify the client (missing reference, intermediary payment, etc.), UNIDENTIFIED_DEPOSIT parks the funds in a suspense account. You cannot refuse incoming funds to an omnibus account — always book immediately.

#![feature("experimental-account-interpolation")]
vars {
  asset $asset
  number $amount
  account $bank_id
  account $platform_name
  string $reference
}
send [$asset $amount] (
  source = @banks:$bank_id:main allowing unbounded overdraft
  destination = @platform:$platform_name:suspense:payin
)
set_tx_meta("reference", $reference)
set_tx_meta("status", "pending_identification")

Once the client is identified, SUSPENSE_RESOLUTION moves the funds from suspense to the correct client account.

#![feature("experimental-account-interpolation")]
vars {
  asset $asset
  number $amount
  account $platform_name
  account $client_id
  string $original_reference
}
send [$asset $amount] (
  source = @platform:$platform_name:suspense:payin
  destination = @clients:$client_id:main
)
set_tx_meta("original_reference", $original_reference)
set_tx_meta("resolution_type", "client_identified")

Client Withdrawal (Payout)#

Payouts are a two-step process:

#![feature("experimental-account-interpolation")]
vars {
  asset $asset
  number $amount
  account $client_id
  account $bank_id
  string $payout_ref
}
send [$asset $amount] (
  source = @clients:$client_id:main
  destination = @banks:$bank_id:payout:$payout_ref
)
set_tx_meta("payout_ref", $payout_ref)
set_tx_meta("status", "reserved")

#![feature("experimental-account-interpolation")]
vars {
  asset $asset
  number $amount
  account $bank_id
  string $payout_ref
  string $bank_reference
}
send [$asset $amount] (
  source = @banks:$bank_id:payout:$payout_ref
  destination = @banks:$bank_id:main
)
set_tx_meta("bank_reference", $bank_reference)
set_tx_meta("status", "settled")

If a payout fails, you reverse the reservation by sending from the staging account back to the client.

Why Not Use @world?#

The @world account is Formance's infinite source/sink. While it simplifies examples, omnibus accounting requires explicit tracking of where funds actually are:

• Bank accounts go negative (overdraft) to represent "we received funds but haven't reconciled yet" — this is intentional and meaningful
• Client accounts are liabilities — their balance represents your obligation
• Suspense accounts enable the "book now, attribute later" pattern that omnibus operations require

Using @world would obscure these distinctions and make reconciliation impossible.

Queries#

The queries section defines reusable lookups:

• CLIENT_BALANCE — get a specific client's position
• PENDING_SUSPENSE — find all unresolved deposits (operational monitoring)
• INFLIGHT_PAYOUTS — track reserved but unsettled withdrawals (risk management)

These leverage the hierarchical account structure — filtering on :suspense:payin matches across all platforms, and :payout: matches all staging accounts.