diff --git a/src/features/organizations/queries/getAllOrganizations.test.ts b/src/features/organizations/queries/getAllOrganizations.test.ts
index b785d1d40..81eb27459 100644
--- a/src/features/organizations/queries/getAllOrganizations.test.ts
+++ b/src/features/organizations/queries/getAllOrganizations.test.ts
@@ -44,15 +44,35 @@ describe('buildAllOrganizationsUrl', () => {
 		expect(buildAllOrganizationsUrl(2, '')).toBe('/Admin/Organization/?status=ne=DELETED&sort(name)&limit(24,37)');
 	});
 
-	it('puts the name filter before the status condition (the API ignores name when status comes first)', () => {
+	it('sends a filter as a relevance search, not a case-sensitive substring match', () => {
 		expect(buildAllOrganizationsUrl(0, 'acme')).toBe(
-			'/Admin/Organization/?name=ct=acme&status=ne=DELETED&sort(name)&limit(0,13)',
+			'/Admin/Organization/?search=acme&status=ne=DELETED&limit(0,13)',
+		);
+	});
+
+	it('omits sort(name) while searching, because the order is the relevance ranking', () => {
+		expect(buildAllOrganizationsUrl(0, 'acme')).not.toContain('sort(');
+	});
+
+	it('still sorts by name when browsing unfiltered', () => {
+		expect(buildAllOrganizationsUrl(0, '')).toContain('sort(name)');
+	});
+
+	it('treats a whitespace-only filter as unfiltered browsing', () => {
+		expect(buildAllOrganizationsUrl(0, '   ')).toBe(
+			'/Admin/Organization/?status=ne=DELETED&sort(name)&limit(0,13)',
+		);
+	});
+
+	it('trims surrounding whitespace off a real filter', () => {
+		expect(buildAllOrganizationsUrl(0, '  acme  ')).toBe(
+			'/Admin/Organization/?search=acme&status=ne=DELETED&limit(0,13)',
 		);
 	});
 
 	it('URI-encodes the filter value', () => {
 		expect(buildAllOrganizationsUrl(0, 'a&b=c')).toBe(
-			'/Admin/Organization/?name=ct=a%26b%3Dc&status=ne=DELETED&sort(name)&limit(0,13)',
+			'/Admin/Organization/?search=a%26b%3Dc&status=ne=DELETED&limit(0,13)',
 		);
 	});
 
@@ -140,13 +160,30 @@ describe('getAllOrganizationsQueryOptions', () => {
 		expect(mockedGet).toHaveBeenNthCalledWith(2, '/Admin/Organization/org-7');
 	});
 
-	it('runs a name search when the value is not an id', async () => {
+	it('runs a relevance search when the value is not an id', async () => {
 		mockedGet.mockResolvedValue({ data: [] });
 
 		await getAllOrganizationsQueryOptions(0, 'Acme').queryFn!({} as never);
 
-		expect(mockedGet).toHaveBeenCalledWith(
-			'/Admin/Organization/?name=ct=Acme&status=ne=DELETED&sort(name)&limit(0,13)',
-		);
+		expect(mockedGet).toHaveBeenCalledWith('/Admin/Organization/?search=Acme&status=ne=DELETED&limit(0,13)');
+	});
+
+	it('finds an organization whatever case the operator types', async () => {
+		mockedGet.mockResolvedValue({ data: [] });
+
+		await getAllOrganizationsQueryOptions(0, 'acme').queryFn!({} as never);
+
+		expect(mockedGet).toHaveBeenCalledWith('/Admin/Organization/?search=acme&status=ne=DELETED&limit(0,13)');
+	});
+
+	it('shares one cache entry across equivalent filters, and requests the normalized term', () => {
+		const key = (v: string) => getAllOrganizationsQueryOptions(0, v).queryKey;
+		expect(key('  acme  ')).toEqual(key('acme'));
+		expect(key('   ')).toEqual(key(''));
+	});
+
+	it('survives a caller that has no filter value at all', () => {
+		expect(() => getAllOrganizationsQueryOptions(0, undefined as unknown as string)).not.toThrow();
+		expect(buildAllOrganizationsUrl(0, undefined as unknown as string)).toContain('sort(name)');
 	});
 });
diff --git a/src/features/organizations/queries/getAllOrganizations.ts b/src/features/organizations/queries/getAllOrganizations.ts
index 34d06aa3b..97265c4ed 100644
--- a/src/features/organizations/queries/getAllOrganizations.ts
+++ b/src/features/organizations/queries/getAllOrganizations.ts
@@ -18,21 +18,34 @@ export interface AllOrganizationsPage {
  * Builds the Harper REST query for one page of the admin organization list.
  * Harper collections return a bare array (no total count), so we request one
  * record past the page boundary to learn whether a next page exists.
+ *
+ * `search` is ranked by relevance server-side, so `sort(name)` is sent only
+ * when browsing unfiltered: with a term the order is the ranking, and the
+ * server ignores any sort. Expects an already-normalized term — see
+ * {@link normalizeSearchValue}.
  */
 export function buildAllOrganizationsUrl(pageIndex: number, nameFilter: string): string {
 	const start = pageIndex * ALL_ORGANIZATIONS_PAGE_SIZE;
+	const search = normalizeSearchValue(nameFilter);
 	const conditions = [
-		// The name filter must precede the status condition: with status first,
-		// the API ignores the name condition entirely.
-		...(nameFilter ? [`name=ct=${encodeURIComponent(nameFilter)}`] : []),
+		// Kept ahead of the status condition, as the name filter had to be.
+		...(search ? [`search=${encodeURIComponent(search)}`] : []),
 		// Terminated organizations stick around with status DELETED; hide them.
 		'status=ne=DELETED',
-		'sort(name)',
+		...(search ? [] : ['sort(name)']),
 		`limit(${start},${start + ALL_ORGANIZATIONS_PAGE_SIZE + 1})`,
 	];
 	return `/Admin/Organization/?${conditions.join('&')}`;
 }
 
+/**
+ * Normalizes a raw filter value. Whitespace-only is unfiltered browsing, not a
+ * search for spaces.
+ */
+export function normalizeSearchValue(value: string | undefined | null): string {
+	return typeof value === 'string' ? value.trim() : '';
+}
+
 export async function getAllOrganizations(pageIndex: number, nameFilter: string): Promise<AllOrganizationsPage> {
 	const { data } = await apiClient.get(buildAllOrganizationsUrl(pageIndex, nameFilter) as '/Organization/');
 	return {
@@ -86,15 +99,19 @@ export async function getOrganizationForClusterPage(clusterId: string): Promise<
 }
 
 /**
- * Query for the admin organization search. When the search value looks like an
- * organization or cluster id (a lowercase `org-`/`clu-` prefix — see
- * {@link detectEntityId}), it resolves that id server-side instead of running a
- * title/name search, so pasting an id jumps straight to the matching org.
+ * Query for the admin organization search. A value that looks like an
+ * organization or cluster id (see {@link detectEntityId}) is resolved by id
+ * instead, so pasting an id jumps straight to the matching org.
  */
 export function getAllOrganizationsQueryOptions(pageIndex: number, searchValue: string) {
-	const entity = detectEntityId(searchValue);
+	// Normalized once, for both the cache key and the request. Keying on the raw
+	// value made `acme`, `acme ` and `  acme` three entries resolving to one
+	// identical request, so a pasted trailing space refetched a search the cache
+	// already held.
+	const search = normalizeSearchValue(searchValue);
+	const entity = detectEntityId(search);
 	return queryOptions({
-		queryKey: ['admin-all-organizations', searchValue, pageIndex],
+		queryKey: ['admin-all-organizations', search, pageIndex],
 		queryFn: () => {
 			if (entity?.kind === 'organization') {
 				return getOrganizationByIdPage(entity.id);
@@ -102,7 +119,7 @@ export function getAllOrganizationsQueryOptions(pageIndex: number, searchValue:
 			if (entity?.kind === 'cluster') {
 				return getOrganizationForClusterPage(entity.id);
 			}
-			return getAllOrganizations(pageIndex, searchValue);
+			return getAllOrganizations(pageIndex, search);
 		},
 		// Keep the previous page on screen while the next one loads.
 		placeholderData: keepPreviousData,