Operators lose credibility fast in counterparty conversations when they use settlement vocabulary loosely. The industry's marketing language treats T+0, intraday, near-real-time, instant, and atomic as broadly interchangeable. They are not interchangeable. Each term refers to a different property, and the wrong term in the wrong context either oversells a system or sells it short. This part is the working glossary, plus the recent history that anchors the vocabulary in real market events.

T+N nomenclature

T+N comes from traditional securities settlement and refers to business days from trade date. T is the trade date itself; T+N is N business days after. It says nothing about what happens within those days, only when settlement finality occurs.

• T+3 was the US equity standard from 1995 until 2017.
• T+2 became the US equity standard in September 2017 and remains the global default for most major securities markets through 2026.
• T+1 became the US equity, corporate-bond, and municipal-bond standard on 28 May 2024. Canada and Mexico moved alongside the US to keep the cross-border settlement window aligned; the EU and UK have committed to follow in 2027.
• T+0 is same-day settlement: trade settles before the end of the trade date. Possible for some products, harder for others (cross-border equities run into time-zone overlap problems with end-of-day cash netting).
• T+N tells you nothing about atomicity. A T+1 settlement can be atomic (Fedwire securities-against-funds) or non-atomic (a typical correspondent-bank chain with sequenced postings). The number is an SLA; atomicity is a structural property.

The May 2024 US T+1 transition is the recent reference point operators are expected to know. It compressed the post-trade workflow by one full business day, eliminated one day of counterparty exposure, freed working capital for clearing members, and increased operational pressure on the same-day affirmation chain.

Intraday

Intraday means within the trading day, but the meaning depends on context. In a clearing context, "intraday margin" is collateral that is calculated, called, and posted multiple times during the trading day rather than once at end of day. In a settlement context, "intraday settlement" can mean settlement that occurs during the day (as distinct from overnight batch processing), or it can mean settlement that is recalculated and re-posted during the day as positions change.

The key precision: intraday is about timing within the trade date. It is not the same as same-day, because same-day can include end-of-day batch settlement on the trade date. It is not the same as real-time, because intraday settlement can still happen in defined sub-day batches. And it is not the same as atomic, because intraday postings can be sequenced and non-atomic.

Intraday is the term most often used loosely by tokenisation marketing. "Intraday repo" usually means real-time return of collateral as positions unwind, but operators in the room should ask: real-time at what granularity, with what cycle frequency, and with what cash-leg arrangement.

Near-real-time

Near-real-time means seconds to a few minutes. It is the language used for systems like FedNow, the UK Faster Payments Service, India's UPI, Singapore's FAST, and the various RTGS modernisation programmes that compress wholesale settlement from end-of-day batches to continuous processing.

Near-real-time is not necessarily atomic, and not necessarily settlement-final on the same definition as a Fedwire transfer. FedNow transfers settle finally in central bank money, but the surrounding workflow (AML, screening, receiving-bank credit posting) can introduce sequencing breaks. UPI is near-real-time in user experience but settles through deferred net cycles; the instant credit is a credit decision by the sending bank, not the underlying settlement event. For a tokenisation operator, "near-real-time" describes a user-experience SLA, not a structural settlement property.

Atomic

Atomic means all-or-nothing, as established in Part 1: both legs of a transaction commit together or both revert, with no observable intermediate state. Atomic is independent of speed (a T+3 settlement can be atomic; a 10-second settlement can be non-atomic), and independent of finality (a transaction can be atomic in the cryptographic sense without being final under the relevant national finality regime). See atomic DvP for the legal-technical separation in detail.

The term is overused in tokenisation marketing because it sounds technical and reassuring. The correct usage is precise: atomic refers specifically to the indivisibility of the multi-leg operation. A token transfer that updates one balance is not "atomic"; it is just a transfer. A DvP transaction that updates a securities balance and a cash balance in a single ledger entry is atomic. A cross-chain swap with a hash time-locked contract that guarantees both legs settle or both revert is atomic with respect to the swap. A cross-chain transfer in which one chain's burn precedes the other chain's mint by ten minutes is not atomic, no matter how the bridge marketing describes it.

The operator's checklist

In a counterparty conversation, the precise vocabulary breaks down as four independent dimensions:

• When does settlement finality occur? T+N, same-day, intraday, near-real-time. This is an SLA dimension.
• Is the multi-leg operation atomic? Yes or no. This is a structural property.
• What is the legal finality regime? Designated settlement system, central bank money, commercial bank money with contractual finality. This is a legal dimension covered in finality definition.
• What is the cash-leg arrangement? Tokenised commercial bank money, tokenised central bank money (wCBDC), regulated stablecoin, off-chain RTGS hop. This drives the supervisory and capital treatment.

Holding all four dimensions separate in a counterparty conversation is the difference between an operator who has thought through the settlement design and one who is repeating marketing language. The next part shows what the structural-property argument is worth in capital terms: the worked example that explains why intraday, atomic settlement actually changes the cost base of a clearing operation.