Closing a concern is a decision, not tidying up. It says the matter has reached an end and records what that end was — which is exactly what someone reading the file in two years needs, and exactly what a concern left quietly open cannot give them.

The three states

A concern is Open, Under review, or Closed. Moving a concern between Open and Under review is done with an update of type Status Change; the status choices there are Open and Under Review only. Closing is done one way: Close Concern.

Who can close one

The Close Concern button is shown only when ARC says you can act on that concern as a lead. For an ordinary concern that is the designated safeguarding lead (DSL) for the home. A registered manager who has not been designated a DSL does not have it. For a concern about a member of staff, the DSL, the registered manager and company admins can close it.

Closing one

Open the concern in the young person's safeguarding file, or from The safeguarding concerns list.
Select Close Concern, at the foot of the concern.
Choose an outcome. The dialog is titled "Close concern?" and says "To close this safeguarding concern, you must record a clear outcome and summary." The Outcome menu offers No further action, Ongoing support, External investigation and Other (describe it). If you choose Other (describe it), write it under Describe the outcome.
Write the Closure summary. The prompt reads "What was done, what was decided, and why the concern can close."
Select Close concern.

Both the outcome and the summary are required. If either is missing, ARC says "Choose an outcome and write a closure summary to close the concern." Cancel leaves the concern exactly as it was.

An allegation closes differently

A concern flagged as an allegation against a member of staff closes against one of five outcome categories, under a menu labelled LADO outcome, and nothing else is accepted:

Substantiated · False · Malicious · Unfounded · Unsubstantiated

ARC shows what each one means as you choose it. A closure summary is required as well. See Allegations against staff.

What closing does

It marks the concern Closed, records the outcome, the summary and the time, and adds a "Concern closed" entry naming the outcome to the timeline.

Nothing is deleted and nothing is hidden. The concern stays in the young person's safeguarding file with everything recorded on it — the narrative, the timeline, the external actions and the documents — and stays visible to exactly the same people as before. It also stays on the DSL's concerns list, under Closed concerns.

Before you close

Nothing in ARC checks these for you. They are still the questions worth asking:

Is every external referral you made recorded, with its reference?
Does the summary say what actually happened, rather than that the matter ended?
Is anything that carries forward — a risk assessment, a plan, a task — already recorded somewhere that will be read?

A concern closed with "resolved" and nothing else is a closed concern and an unanswered question.