Most screening workflows assume the firm chooses when to act. A sanctions surge removes that: the list changes on someone else's schedule, the measure applies on publication, and your obligation exists before anyone at your firm has read the notice.
Everything that determines how well the day goes was therefore decided before it started.
The window you do not control
Between a designation being published and your screening engine holding it, there is a gap. Nothing in the response can shorten it on the day, because it is a function of how often you ingest list changes, which was configured months earlier.
That is why the rail above gives the largest share of the first day to a stretch labelled as the part you do not control. Firms tend to focus on triage speed, which is visible and feels like the work. The gap in front of it is usually longer and is where the actual exposure sits.
What "re-screen the book" really means
Not the new applicants. The whole population: every customer, every beneficial owner, every counterparty, matched against the amended list rather than yesterday's cached copy.
The harder half is ownership and control. Designations commonly reach entities owned or controlled by a designated person, so a prohibited relationship can exist without the customer's own name appearing on any list. Answering that requires beneficial ownership data good enough to traverse, which most firms discover the quality of during a surge rather than before one.
Triage is a separation problem
A surge produces a spike of candidates, and most of them are false. The response is not judged on how many alerts were generated but on how quickly the genuine ones were separated from the rest and acted on.
Tuned matching, whitelists that have already dismissed known false positives, and verified identity attributes available in the review screen all pay off here specifically, because they compress a queue that has to be cleared against a clock.
The record has to be made during
Afterwards, the question is narrow and precise: what did you know, when did you know it, and what did you do between those two moments?
A file assembled the following week is a narrative. It describes what the firm believes happened rather than showing it. The only reviewable answer is one written while the response was running, which makes recording part of the workflow rather than a task that follows it.
For the standing capability this tests, see PEP and sanctions screening and transaction monitoring. For the ownership data the hard half depends on, see Know Your Business.