diff --git a/plugins/sonarqube/src/components/SonarQubeCard/SonarQubeCard.tsx b/plugins/sonarqube/src/components/SonarQubeCard/SonarQubeCard.tsx
index d8aaec04f2..af91bc5469 100644
--- a/plugins/sonarqube/src/components/SonarQubeCard/SonarQubeCard.tsx
+++ b/plugins/sonarqube/src/components/SonarQubeCard/SonarQubeCard.tsx
@@ -98,7 +98,11 @@ export const SonarQubeCard = ({
   const { projectKey: projectTitle, projectInstance } = useProjectInfo(entity);
 
   const { value, loading } = useAsync(
-    async () => sonarQubeApi.getFindingSummary(projectTitle, projectInstance),
+    async () =>
+      sonarQubeApi.getFindingSummary({
+        componentKey: projectTitle,
+        projectInstance: projectInstance,
+      }),
     [sonarQubeApi, projectTitle],
   );
 
diff --git a/plugins/sonarqube/src/components/useProjectKey.test.ts b/plugins/sonarqube/src/components/useProjectKey.test.ts
new file mode 100644
index 0000000000..be83c236df
--- /dev/null
+++ b/plugins/sonarqube/src/components/useProjectKey.test.ts
@@ -0,0 +1,100 @@
+/*
+ * Copyright 2022 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import {
+  isSonarQubeAvailable,
+  SONARQUBE_PROJECT_INSTANCE_SEPARATOR,
+  SONARQUBE_PROJECT_KEY_ANNOTATION,
+  useProjectInfo,
+} from './useProjectKey';
+import { Entity } from '../../../../packages/catalog-model';
+
+const createDummyEntity = (sonarqubeAnnotationValue: string): Entity => {
+  return {
+    apiVersion: '',
+    kind: '',
+    metadata: {
+      name: 'dummy',
+      annotations: {
+        [SONARQUBE_PROJECT_KEY_ANNOTATION]: sonarqubeAnnotationValue,
+      },
+    },
+  };
+};
+
+describe('isSonarQubeAvailable', () => {
+  it('returns true if sonarqube annotation defined', () => {
+    const entity = createDummyEntity('dummy');
+    expect(isSonarQubeAvailable(entity)).toBe(true);
+  });
+  it('returns false if sonarqube annotation empty', () => {
+    const entity = createDummyEntity('');
+    expect(isSonarQubeAvailable(entity)).toBe(false);
+  });
+  it('returns false if sonarqube annotation not defined', () => {
+    const entity = {
+      apiVersion: '',
+      kind: '',
+      metadata: {
+        name: 'dummy',
+        annotations: {},
+      },
+    };
+    expect(isSonarQubeAvailable(entity)).toBe(false);
+  });
+});
+
+describe('useProjectInfo', () => {
+  const DUMMY_INSTANCE = 'dummyInstance';
+  const DUMMY_KEY = 'dummyKey';
+  it('parse annotation with key and instance', () => {
+    const entity = createDummyEntity(
+      DUMMY_INSTANCE + SONARQUBE_PROJECT_INSTANCE_SEPARATOR + DUMMY_KEY,
+    );
+    expect(useProjectInfo(entity)).toEqual({
+      projectInstance: DUMMY_INSTANCE,
+      projectKey: DUMMY_KEY,
+    });
+  });
+  // compatibility with previous mono-instance sonarqube config
+  it('parse annotation with only key', () => {
+    const entity = createDummyEntity(DUMMY_KEY);
+    expect(useProjectInfo(entity)).toEqual({
+      projectInstance: undefined,
+      projectKey: DUMMY_KEY,
+    });
+  });
+  it('handle empty annotation', () => {
+    const entity = createDummyEntity('');
+    expect(useProjectInfo(entity)).toEqual({
+      projectInstance: undefined,
+      projectKey: undefined,
+    });
+  });
+  it('handle non-existent annotation', () => {
+    const entity = {
+      apiVersion: '',
+      kind: '',
+      metadata: {
+        name: 'dummy',
+        annotations: {},
+      },
+    };
+    expect(useProjectInfo(entity)).toEqual({
+      projectInstance: undefined,
+      projectKey: undefined,
+    });
+  });
+});
diff --git a/plugins/sonarqube/src/components/useProjectKey.ts b/plugins/sonarqube/src/components/useProjectKey.ts
index fbe12b5b5d..7a5a428f49 100644
--- a/plugins/sonarqube/src/components/useProjectKey.ts
+++ b/plugins/sonarqube/src/components/useProjectKey.ts
@@ -25,7 +25,7 @@ export const isSonarQubeAvailable = (entity: Entity) =>
 /**
  * Try to parse sonarqube information from an entity.
  *
- * If part or all info are not found, they will default to an empty string
+ * If part or all info are not found, they will default to undefined
  *
  * @param entity entity to find the sonarqube information from.
  * @return a ProjectInfo properly populated.
@@ -33,11 +33,11 @@ export const isSonarQubeAvailable = (entity: Entity) =>
 export const useProjectInfo = (
   entity: Entity,
 ): {
-  projectInstance: string;
-  projectKey: string;
+  projectInstance: string | undefined;
+  projectKey: string | undefined;
 } => {
-  let projectInstance = '';
-  let projectKey = '';
+  let projectInstance = undefined;
+  let projectKey = undefined;
   const annotation =
     entity?.metadata.annotations?.[SONARQUBE_PROJECT_KEY_ANNOTATION];
   if (annotation) {