T+0 Settlement: Why the SEC Stopped at T+1

Updated October 2026. First published March 2024.

The SEC looked at T+0 and decided against it when it adopted T+1 on February 15, 2023. It said a cycle shorter than T+1 "could ultimately produce considerable additional benefits to investors," but that T+0 would first need the industry to solve a list of problems, and would take longer and cost more than T+1. The first version of this post called T+0 "an inevitable next step" and pointed to blockchain and quantum computing. No regulator has set a T+0 date for U.S. equities since, and the European authorities that set T+1 dates in 2025 chose to move to T+1 first.

What the SEC Said in 2023

The T+1 adopting release lists the impediments to T+0 that the proposal, a 2021 industry report, and comment letters had raised:

multilateral netting,
institutional trade processing,
securities lending practices,
money settlement systems,
mutual fund and ETF processing,
transaction funding requirements,
corporate action processing.

Because the industry hadn't developed solutions, the SEC said it "cannot reasonably provide estimates" of how long a move to T+0 would take or what it would cost. It called T+1 "the more prudent and practical approach" and said that after the transition its staff would keep working with the industry and other regulators "to assess the future feasibility of a T+0 settlement standard cycle."

What DTCC and Other Commenters Said

DTCC's comment letter, as the release quotes it, said moving the whole industry to T+0 "would necessitate significant changes in industry conventions and major investments in automating processes and technology that will greatly exceed similar investments needed for T+1." DTCC argued for a "full review" of what T+0 would take once the industry was well into T+1 work.

Other commenters were specific about where it breaks. One said T+0 would mean moving currency in real time at hours when that isn't possible, with banks, wire systems, custodians, lenders, and money market funds staffed "well into the evening." Another said batch processing couldn't capture every trade by the close, so clearing agencies would net intraday and make several margin calls a day. The same commenter said advisers would struggle to allocate in real time and prime brokers would have to rebuild how they capture allocations and disaffirm trades. It also said T+0 would require "complete dematerialization of securities."

DTCC's public pages on accelerated settlement, as of October 2026, cover T+1 in Europe and Asia-Pacific. They don't discuss a market-wide move to T+0. Where "T+0" does appear, it describes same-day trade matching in DTCC's CTM service, which is the trade-date work T+1 already demanded.

Europe Chose T+1 First

The U.K. Accelerated Settlement Taskforce said in March 2024 that T+0 or atomic settlement is "technically possible today," but that there was "clear consensus" against going from T+2 to T+0 in one step. Its Technical Group repeated in February 2025 that a move to T+0 "should not take place until after the move to T+1."

The EU's T+1 regulation of October 8, 2025 says the shorter cycle "would not prevent central securities depositories from voluntarily settling transactions on the same date as the trade date, where technologically feasible." Its recitals also note that EU CSDs already settle "a non-negligible number of transactions on a T+0 basis." The same U.K. report noted that India's securities regulator had consulted on optional T+0 and optional instant settlement.

T+0 Is Already Allowed in the U.S.

Rule 15c6-1(a) bars a broker-dealer from entering a contract that settles "later than the first business day after the date of the contract" unless the parties expressly agree otherwise. It sets a maximum. Nothing in it stops two parties from settling a trade on trade date if they can. What doesn't exist is a requirement that everyone does.

What Would Have to Change

Taking the SEC's list in operational terms:

Netting. NSCC's Continuous Net Settlement nets each member's trades in a security into one position. NYSE's comment letter said T+0 would eliminate "the benefits of netting" and require "that every transaction be funded instantly and individually." Netting in intraday cycles would keep some of it, with the intraday margin calls other commenters warned about.
Funding. Cash has to be in place when the trade settles, the same day. For a non-U.S. investor that means buying dollars for same-day value; for a retail customer it means funding the account before trading.
Lending. A lender that sells a loaned security would need the shares back the same day. Under T+1 the recommended recall time is already 11:59 p.m. ET on trade date (see securities lending under T+1).
Allocation and affirmation. These would have to happen in real time, not by the 9:00 p.m. ET cutoff advisers work to now (see our post for investment advisers).
Regulation T. The payment period is defined as the settlement cycle plus two business days, so the formula would give a two-day period at T+0 (see Regulation T after T+1).

Most of that list is the same work T+1 made urgent: trade-date allocation, current settlement instructions, automated recalls, and funding that doesn't wait for a next-day FX trade. That's the useful part for an operations team. Firms that finished that work for T+1 have done much of the groundwork anyone would need for a shorter cycle, whether or not a regulator ever sets one.

This post is for informational purposes only and does not constitute legal advice. For guidance on specific regulatory obligations, consult your counsel or compliance advisor.