Textbook/Unit 01

Payments & money movement

Cards, bank transfers, instant payments, ledgers, and settlement.

Unit 01 / The big picture

One payment. Two different tracks.

Two parallel tracks describe a payment. The instruction track runs from customer through provider and payment rail to receiving bank. The settlement track runs from payer bank through the settlement system to payee bank. A ledger between the tracks records obligations; matching a message to a ledger entry does not prove settlement. Timing and finality depend on the rail.

Enlarge to read every label and explore the connections

Instructions describe what should happen. Settlement changes who has discharged a financial obligation; the ledger must account for both.

  1. Follow the instruction across the top row.

  2. Trace the separate settlement obligation below.

  3. Use independent records to reconcile the two.

Inside this unit

5 chapters
One payment. Three different truths.
1.1 / 15 min read

Money movement and the risk map

Follow a payment from a tap on a screen to a settled obligation.

Read chapter
Approval is the beginning
1.2 / 15 min read

Cards, authorization, and disputes

Understand card states, authentication, liability, and delayed feedback.

Read chapter
Verified does not mean authorized
1.3 / 15 min read

ACH, bank debits, and returns

Separate account access, authorization, settlement, and return exposure.

Read chapter
The control window closes fast
1.4 / 15 min read

Instant payments and cross-border transfers

Design for finality, payee risk, foreign exchange, and international handoffs.

Read chapter
Balance the books. Explain the difference.
1.5 / 15 min read

Ledgers, reconciliation, and settlement risk

Make balances explainable and prevent money from appearing twice.

Read chapter