What Central Matching Automates Under T+1

Updated October 2026, with DTCC's 2025 matching data. First published January 2024.

An institutional trade needs three messages before it can settle: the allocation, the confirmation, and the affirmation. Since May 28, 2024, SEC Rule 15c6-2 has required a broker-dealer to get them done as soon as technologically practicable and no later than the end of trade date, either through written agreements with the other parties or through written policies and procedures. DTC's practical deadline is 9:00 p.m. ET. This post covers what the central matching tools do inside that window and what they leave to you. Our post on AI and T+1 settlement covers the narrower question of where machine learning fits.

Three Messages Between Three Parties

The investment manager executes a block trade, then tells the broker how to split it across its accounts. That's the allocation. The broker sends back the trade details for each account, which is the confirmation. The manager, or the custodian acting for the account, agrees that the details are right. That's the affirmation. An affirmed trade then goes to DTC for settlement.

Each message can be sent by hand, through a vendor screen, or file to file. Under T+2, a missed message had a day to be fixed. Under T+1 it has the rest of the evening.

Who Runs Central Matching

The SEC treats central matching as a clearing agency function. As of the 2023 adopting release, three firms held exemptions from registration to provide it: DTCC ITP Matching (US), Bloomberg STP, and SS&C Technologies. In its T+1 adopting release, the SEC said it believed only one of the three was providing the service in the U.S. That one is DTCC's, and it runs three services that matter here:

CTM, which matches the manager's allocations against the broker's confirmations;
TradeSuite ID, the U.S. confirmation and affirmation service;
ALERT, a database of standing settlement instructions (SSIs) that fills in where each account settles.

The same release created Rule 17Ad-27, which requires each central matching provider to report to the SEC every year on straight-through processing, with month-by-month data on manual and automated activity. DTCC ITP Matching filed its second report, for calendar 2025, in February 2026. It's the most detailed public picture of how U.S. institutional trades get processed, and the numbers below come from it.

What the Tools Automate

Matching and affirmation are the big one. When a manager and a broker both use CTM's Match to Instruct (M2i) workflow, a match in CTM affirms the trade in TradeSuite ID automatically. In 2025, 99.55% of M2i trades were affirmed by the 9 p.m. cutoff. Trades affirmed by hand in TradeSuite ID averaged about 89%. M2i carried 53% of eligible CTM volume, and 603 buy-side clients were set up for it by December 2025.

Settlement instructions come next. ALERT enriched about 98% of CTM block trades with SSIs in 2025, and fewer than 0.5% were enriched by hand. Our post on SSIs and DTCC ALERT explains why a one-day window raises the cost of a wrong instruction.

Data entry has almost disappeared from matching. Allocations typed into the CTM screen were 0.01% to 0.02% of U.S. allocations each month. Nearly everything arrives by file or message.

What They Don't Automate

The first gap is timing. In 2025, 69.6% of the U.S. allocations sent to CTM arrived between 4 p.m. and 7 p.m. ET on trade date, and 29% arrived before 4 p.m. Equity allocations bunch up after the close more than debt allocations do. Matching can't make a manager allocate earlier.

The second is the firms that aren't connected. In the bilateral flow, where custodians and managers affirm for themselves, 88% to 93% of trades were affirmed by 9 p.m. in 2025. DTCC attributes the gap to custodians and managers outside the U.S. who aren't on automatic affirmation. Before go-live, DTCC offered smaller manual managers a discounted "T+1 Automation Package" and later reported "minimal Client uptake." It repackaged the offer in September 2025.

The third is bad data upstream. Matching compares what each side sends, so a wrong account or a stale instruction can match perfectly and still fail. DTCC told clients that CTM would start rejecting allocations missing a place-of-settlement (PSET) field in September 2026. At the end of 2025, 55% of CTM clients were populating it on every allocation.

What Stays With the Broker-Dealer

Using central matching doesn't satisfy Rule 15c6-2 by itself. A broker-dealer that relies on policies and procedures has to identify the systems it uses with advisers and custodians, set target times on trade date for each step, describe how it investigates discrepancies and handles a counterparty that's running late, and measure, monitor, and document its same-day completion rates. CTM and TradeSuite ID give you the data for the last item. The rest is your procedure, and our post on Rule 15c6-2 in practice covers the choice between written agreements and policies.

Advisers have their own piece. The same release amended Advisers Act Rule 204-2 so that registered advisers make and keep records of the allocations, confirmations, and affirmations for these trades. An adviser may use a third party to keep them, but the obligation stays with the adviser.

What to Check This Quarter

Your affirmation rate by counterparty and by hour, from your TradeSuite ID data. The counterparties below 90% are your evening workload.
Which institutional clients aren't on M2i, and what it would take to move them.
Whether your procedures name a target time for each step, as Rule 15c6-2(b)(2) requires.
PSET population on your allocations, since DTCC planned to start rejecting allocations without it in September 2026.

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.