Card Network Settlement

Prerequisite: Payment Rails

A customer taps their card at a coffee shop. The terminal displays “Approved” in 1.8 seconds. The merchant assumes the money is theirs. It is not. The issuing bank has promised to pay, but no funds have moved. The acquirer will not receive settlement for 24–48 hours. The merchant’s bank account will not reflect the deposit for another business day after that. Between the tap and the funded deposit, three distinct systems run — authorization, clearing, and settlement — each with its own message format, failure mode, and reconciliation requirement.

If your platform sits anywhere in this chain — as an issuer-processor, an acquirer, a payment facilitator, or a BaaS provider — you must model all three phases independently. Treating “approved” as “settled” will produce incorrect balances, premature payouts, and reconciliation breaks that compound daily.

The Three-Phase Cycle

Card transactions separate into three phases because the participants need different things at different times.

Phase	Timing	Purpose	System
Authorization	Real-time (1–3 seconds)	“Will the issuer pay?”	Online, synchronous
Clearing	Batch (hours after transaction)	“What are the final transaction details?”	Batch file exchange
Settlement	Next business day	“Move the money”	Net settlement via settlement bank

Authorization is synchronous and latency-sensitive. Clearing is asynchronous and accuracy-sensitive. Settlement is a banking operation — funds move between depository institutions through the network’s settlement bank (Visa uses JPMorgan Chase; Mastercard uses a network of settlement banks per currency).

The separation exists because the issuer must decide in real time whether to approve, but the final transaction amount may differ from the authorized amount (tips, fuel pumps, partial shipments). Clearing captures the final amount. Settlement moves the net position.

Authorization Flow

A card authorization traverses five parties in a round trip that must complete in under 3 seconds.

Cardholder → Merchant POS → Acquirer Processor → Card Network → Issuer Processor
                                                                      ↓
Cardholder ← Merchant POS ← Acquirer Processor ← Card Network ← Approve/Decline

The message format is ISO 8583 — a binary protocol with a bitmap indicating which data elements are present. A typical authorization request (message type 0100) includes the primary account number, transaction amount, merchant category code, terminal ID, and a cryptogram for chip transactions.

Field	ISO 8583 element	Purpose
PAN	DE 2	Card number (or token)
Amount	DE 4	Transaction amount in minor units
MCC	DE 18	Merchant category code
POS entry mode	DE 22	How the card was read (chip, tap, swipe, manual)
Network ID	DE 24	Visa, Mastercard, etc.
Authorization code	DE 38	Issuer’s approval code (in response)
Response code	DE 39	00 = approved, 05 = declined, 51 = insufficient funds

The issuer has roughly 1 second to decide. That decision involves balance check, fraud scoring, velocity checks, and sanctions screening — all within that budget. A timeout at the issuer produces a stand-in authorization from the network, which means the network approved on the issuer’s behalf. The issuer inherits the risk.

Stand-in authorizations (STIP) mean the network approved a transaction the issuer never saw. If your issuer-processor goes down for 30 seconds during peak hours, the network will approve transactions against your cardholders’ accounts without your fraud checks running. You inherit every one of those transactions.

Dual-Message vs Single-Message

Credit card transactions use a dual-message flow. The authorization (message type 0100) and the capture (message type 0220) are separate messages, often hours or days apart. The merchant authorizes at the point of sale, then submits the capture in a batch at end of day.

Debit PIN transactions use a single-message flow. The authorization and financial capture happen in one message (message type 0200). The cardholder enters their PIN, the issuer approves and commits the funds in a single round trip. There is no separate capture step.

Flow	Auth message	Capture	Settlement gap	Use case
Dual-message	0100	0220 (batch, hours later)	Auth amount may differ from capture	Credit cards, signature debit
Single-message	0200	Included in auth	Final at auth time	PIN debit, ATM withdrawals

The dual-message gap creates the authorization hold — the issuer reserves funds at auth time but does not finalize the amount until capture. A hotel authorizes $500 for incidentals. The guest checks out with $47 in minibar charges. The capture is $47, and the $500 hold releases. If the hold does not release promptly, the cardholder’s available balance is wrong for days.

Clearing

Clearing is the batch process where acquirers submit finalized transaction records to the network and the network distributes them to issuers.

Visa’s clearing system uses Transaction Clearing (TC) records. The acquirer submits TC05 records (original financial transactions), and the network generates TC07 records (fees, adjustments, chargebacks). These records flow through Visa’s VisaNet clearing system as fixed-format batch files.

Mastercard uses the Integrated Product Messages (IPM) format — a similar batch file system with its own record types.

The clearing file contains the final transaction amount (which may differ from the authorization amount), the interchange qualification data (which determines the fee tier), and the merchant data needed for the cardholder’s statement.

Clearing data element	Purpose	Why it matters
Final amount	What the merchant actually charged	May differ from auth amount (tips, partial captures)
Interchange qualification	Which fee tier applies	Determines cost to acquirer
Merchant descriptor	What appears on the statement	Incorrect descriptors drive chargebacks
Authorization code	Links clearing to the original auth	Mismatches create exceptions

A clearing record that cannot be matched to its authorization creates an exception item. The acquirer must resolve it — usually by resubmitting with corrected data or accepting a higher interchange tier as a penalty. High exception rates (above 1% of transactions) indicate a systemic issue in the acquirer’s capture pipeline.

Settlement

Settlement is when money moves. The network calculates the net position for each participant — what each issuer owes each acquirer, minus interchange — and instructs the settlement bank to execute the transfers.

Visa nets all transactions for a settlement period (typically one business day), calculates each member’s net position, and instructs JPMorgan Chase to debit issuers and credit acquirers. An issuer that processed $10M in cardholder purchases and received $200K in merchant refunds has a net settlement obligation of $9.8M minus interchange fees.

The settlement amount an acquirer receives is the gross transaction volume minus interchange minus network assessment fees:

acquirer_settlement = gross_volume - interchange - assessment_fees

# Example: $1,000,000 in Visa credit transactions
interchange  = $1,000,000 × 0.0185  = $18,500   # 1.85% average
assessment   = $1,000,000 × 0.0014  = $1,400    # 0.14% Visa assessment
acquirer_net = $1,000,000 - $18,500 - $1,400 = $980,100

The acquirer then pays the merchant from this net amount, retaining the acquirer markup (the merchant discount rate minus interchange and assessments).

See Executing Money Flows. Card settlement is a net settlement system — participants exchange net positions, not individual transactions. The settlement bank moves the net amounts between member banks’ accounts.

Interchange Economics

Interchange is the fee the issuer charges the acquirer for each transaction. The cardholder never sees it directly, but it funds rewards programs, fraud protection, and the issuer’s operating costs.

Card type	Typical interchange (US)	Who pays	Who receives
Credit (rewards)	1.8–2.4%	Acquirer (passed to merchant)	Issuer
Credit (basic)	1.5–1.7%	Acquirer	Issuer
Signature debit	0.8–1.2%	Acquirer	Issuer
PIN debit	$0.21 + 0.05% (Durbin regulated)	Acquirer	Issuer
Debit (exempt from Durbin)	0.7–1.0%	Acquirer	Issuer

The Durbin Amendment (2011) capped debit interchange for issuers with over $10B in assets at $0.21 + 0.05% per transaction — roughly $0.24 on a $50 purchase versus $0.50–$0.75 pre-regulation. This cap applies only to regulated issuers. Smaller banks and credit unions are exempt, which is why their debit cards often carry higher interchange.

Interchange qualification depends on how the transaction was processed. A chip-read transaction with address verification qualifies for the best rate. A manually keyed transaction without AVS qualifies for a higher (more expensive) tier. The difference between tiers can be 0.5–1.0% — on $100M annual volume, that is $500K–$1M in additional cost for the acquirer.

Chargebacks

A chargeback reverses a settled transaction. The cardholder disputes the charge with their issuer, the issuer debits the acquirer, and the acquirer debits the merchant. The dispute lifecycle can span 120 days.

Day 0:   Cardholder disputes charge with issuer
Day 1-5: Issuer files chargeback with network (reason code assigned)
Day 5-7: Acquirer receives chargeback notification
Day 7-30: Merchant gathers evidence for representment
Day 30-45: Acquirer submits representment to network
Day 45-75: Issuer reviews and accepts or escalates to arbitration
Day 75-120: Network arbitration (if needed), final ruling

Reason codes classify the dispute. Visa uses a four-digit system (10.4 = “Other Fraud — Card Absent Environment”). Mastercard uses a similar numeric scheme. The reason code determines what evidence the merchant must provide for representment.

Dispute category	Visa reason codes	Merchant win rate	Required evidence
Fraud	10.x	20–30%	3DS authentication proof, device fingerprint, delivery confirmation
Authorization	11.x	40–50%	Signed receipt, chip verification
Processing errors	12.x	60–70%	Correct transaction records
Consumer disputes	13.x	30–40%	Terms of service, refund policy, communication records

A merchant’s chargeback ratio — disputes divided by total transactions — triggers monitoring programs at 0.9% (Visa) or 1.0% (Mastercard). Exceeding these thresholds leads to fines, increased monitoring, and eventual termination from the network. For a platform processing $50M/month, a 1% chargeback rate means $500K in disputed transactions per month and potential network penalties.

Stablecoin Settlement

Visa began settling in USDC on Ethereum in 2021 and expanded to Solana in 2023. Instead of waiting for traditional banking hours and net settlement through JPMorgan Chase, participating acquirers receive USDC settlement in near real-time.

The flow changes the settlement phase, not authorization or clearing. The cardholder still taps a Visa card. The authorization still runs through VisaNet. The clearing still produces TC records. But the settlement leg sends USDC instead of a Fedwire transfer.

Settlement method	Settlement time	Cutoff dependency	Weekend/holiday availability
Traditional (Fedwire)	T+1 to T+2 business days	Banking hours, Fedwire schedule	No — delayed to next business day
USDC on Ethereum	Minutes to hours	None — 24/7/365	Yes
USDC on Solana	Seconds to minutes	None — 24/7/365	Yes

Visa reported over $225M in USDC settlement volume in the first half of 2025 alone, with cumulative volume exceeding $20B since launch. The operational advantage is not speed alone — it is eliminating the settlement calendar. A Friday evening transaction that would settle Tuesday in the traditional flow settles within hours via USDC.

See Payment Rails. Stablecoin settlement changes the last mile of the three-phase cycle — it does not replace the authorization or clearing phases. The card network still intermediates the transaction.

Authorization Holds

The gap between authorization and settlement creates a temporary state where funds are committed but not moved. The issuer marks the authorized amount as unavailable (reducing the cardholder’s available balance) but does not debit the account until clearing.

Holds create three operational problems.

Hold amount mismatches. Gas stations authorize $1 to verify the card, then capture $45 after fueling. Hotels authorize $500 for a two-night stay, then capture $312 at checkout. The hold must release the difference, and release timing varies by issuer — some release immediately on capture, others hold for 3–5 business days.

Expired holds. Visa mandates that authorization holds expire after 7 days for most merchant categories (30 days for hotels and car rentals). If the merchant does not capture within that window, the hold drops and the cardholder’s available balance increases. If the merchant then submits a late capture, it processes without a matching auth — creating a force-post that may be flagged or declined.

Partial captures. An e-commerce order authorized for $100 ships in two boxes. The merchant captures $60 for the first shipment and $40 for the second. The $100 hold must decrement by $60 on the first capture and release the remaining $40 only when the second capture arrives — or release it after the hold expiration window if the second shipment never ships.

Network-Specific Differences

Visa, Mastercard, and American Express process transactions through architecturally similar systems with operationally significant differences.

Dimension	Visa	Mastercard	American Express
Network model	Four-party (issuer, acquirer, network, merchant)	Four-party	Three-party (Amex is issuer and network)
Clearing format	TC05/TC07	IPM	Proprietary
Settlement bank (US)	JPMorgan Chase	Multiple per currency	Amex settles directly
Auth timeout	15 seconds	30 seconds	Varies
Chargeback threshold	0.9%	1.0%	Varies by merchant agreement
Stablecoin settlement	USDC (Ethereum, Solana)	Exploring (not live)	Not announced

American Express’s three-party model means Amex is both the network and the issuer for most cards. There is no interchange in the traditional sense — Amex charges the merchant a single discount rate (typically 2.2–3.5%) and retains all of it. This simplifies settlement (no interchange calculation between separate issuers and acquirers) but limits merchant acceptance because the cost is higher than Visa/Mastercard interchange plus acquirer markup.

For engineers building issuer-processing or acquiring systems, the practical differences are in message formats, timeout handling, and settlement file parsing. The business logic — authorize, clear, settle — is the same across all three networks. The implementation details — field positions in clearing files, reason code taxonomies, hold expiration rules — are network-specific and change with each specification update.