GLOBAL PAYMENTS KNOWLEDGEISO 20022 / SWIFT / SEPA / MT / MX
PAYMENTSSIGNAL

The interactive academy for the standards, messages, and rails that move money.

GET IN TOUCH
STR (BRAZIL RTGS)

Queued at the BCB: an STR payment short of reserves

Trigger: Bank Alfa's reserve account at the Banco Central do Brasil lacks the funds to cover a high-value STR transfer.

Contributor Shubham Mathure

What operations sees first: A high-value wholesale payment does not settle at once; it waits until reserves cover it.

WHERE IS THE MONEY?

No money moved while queued — Bank Alfa's reserve account was untouched until cover arrived.

DID SETTLEMENT HAPPEN?

Settlement was deferred until reserves were available, then completed gross and final.

WHO ACTS NEXT?

Bank Alfa (sending bank) Bank Alfa manages its reserve position and uses the interbank market to fund high-value STR transfers.

PLAY THE EXCEPTION

Trigger: Bank Alfa's reserve account at the Banco Central do Brasil does not hold BRL 3,000,000.00 at the moment the STR checks it.

STEP 1 / 5MESSAGE

Bank Alfa submits the STR transfer

Bank Alfa (sending bank) → STR (Reserve Transfer System)

The sending bank submits a Reserve Transfer System message to move a high-value interbank obligation to Nordbank. Nothing has moved yet — it is a request, not the money.

Step 1 of 5: Bank Alfa submits the STR transfer

  1. 01Message
    Bank Alfa submits the STR transferBank Alfa (sending bank) → STR (Reserve Transfer System)
  2. 02Message
    STR checks Bank Alfa's reserve balanceSTR (Reserve Transfer System) → Banco Central do Brasil
  3. 03 · EXCEPTION PATHMessage
    The transfer cannot settle yetSTR (Reserve Transfer System) → Bank Alfa (sending bank)
  4. 04 · EXCEPTION PATHProcessing
    Bank Alfa sources liquidity in the interbank marketBank Alfa (sending bank)
  5. 05 · EXCEPTION PATHSettlement
    The funded transfer settlesBank Alfa (sending bank) → Nordbank (receiving bank)
  6. OUTCOME
    Funds
    The obligation is still owed; Nordbank is paid only once Bank Alfa funds its reserve account and the transfer settles.
    Settlement
    Settlement waited on liquidity — the payment did not settle until the reserve account was covered.
    Who acts next
    Bank Alfa (sending bank) — Bank Alfa manages its intraday liquidity and uses the interbank market so high-value transfers do not stall before the STR closes for the day.
Full step-by-step text (works without JavaScript)
  1. 01Message
    Bank Alfa submits the STR transferBank Alfa (sending bank) → STR (Reserve Transfer System)

    The sending bank submits a Reserve Transfer System message to move a high-value interbank obligation to Nordbank. Nothing has moved yet — it is a request, not the money.

  2. 02Message
    STR checks Bank Alfa's reserve balanceSTR (Reserve Transfer System) → Banco Central do Brasil

    The STR asks the Banco Central do Brasil whether Bank Alfa's reserve account holds the funds now — an RTGS rail will not create reserves a bank does not have.

  3. 03 · EXCEPTION PATHMessage
    The transfer cannot settle yetSTR (Reserve Transfer System) → Bank Alfa (sending bank)

    An RTGS system will not settle reserves it does not have. Without cover, the STR queues or holds the transfer rather than settling it, and tells Bank Alfa.

  4. 04 · EXCEPTION PATHProcessing
    Bank Alfa sources liquidity in the interbank marketBank Alfa (sending bank)

    The STR runs in business hours, so Bank Alfa borrows reserves from another bank in the interbank market to cover the queued high-value transfer.

  5. 05 · EXCEPTION PATHSettlement
    The funded transfer settlesBank Alfa (sending bank) → Nordbank (receiving bank)

    With cover in place, the Banco Central do Brasil settles the payment across the two reserve accounts, individually and finally.

    • DR Bank Alfa's reserve account at the BCB — BRL 3,000,000.00
    • CR Nordbank's reserve account at the BCB — BRL 3,000,000.00
  6. OUTCOME
    Funds
    The obligation is still owed; Nordbank is paid only once Bank Alfa funds its reserve account and the transfer settles.
    Settlement
    Settlement waited on liquidity — the payment did not settle until the reserve account was covered.
    Who acts next
    Bank Alfa (sending bank) — Bank Alfa manages its intraday liquidity and uses the interbank market so high-value transfers do not stall before the STR closes for the day.

THE TIMELINE

  1. 01Bank Alfa (sending bank)
    Submits a BRL 3,000,000.00 STR transfer for real-time gross settlement in reserves.
  2. 02STR (Reserve Transfer System)
    Finds Bank Alfa's reserve-account balance insufficient and queues the transfer rather than rejecting it.
  3. 03Bank Alfa
    Sources liquidity in the interbank market to cover its reserve account, since the STR runs in business hours.
  4. 04Banco Central do Brasil
    Settles the released transfer gross in central bank reserves, final and irrevocable.

Resolution: The transfer is deferred, not lost. Once reserves cover it, the BCB settles it gross and final. Unlike the 24/7 SPI, the STR runs in business hours and banks manage liquidity via the interbank market.

LEARN THE CONCEPTS

Sources for this scenario2
  1. Official requirement

    Pix, the Instant Payment System (SPI) and the Reserve Transfer System (STR) ↗ — Banco Central do Brasil · STR settlement

    Describes Pix, the instant payment platform created and managed by the Banco Central do Brasil: 24/7 real transfers addressed by a Pix key (phone, email, tax ID or random string) resolved through the DICT directory, settled individually and one-to-one, final and irrevocable, over the Instant Payment System (SPI), an RTGS available every day; and the STR (Reserve Transfer System), Brazils wholesale RTGS for interbank reserve transfers. · Checked 2026-07-14

    Pix settles over the SPI (RTGS) in about three seconds; the STR is the wholesale reserve-transfer RTGS operated by the BCB.

  2. Simplified educational illustration

    Payments Signal editorial teaching models — Payments Signal

    This site's own simplified teaching models. · Checked 2026-07-12

    What this simplifies: Single-cycle teaching model; participant-specific handling and exact timings vary.

    Used wherever diagrams, scenarios, figures, or example values are didactic constructions rather than sourced facts; every such use carries a simplifications disclosure. All people, companies, banks, and list entries in examples are fictional.