diff --git a/homeassistant/components/sabnzbd/config_flow.py b/homeassistant/components/sabnzbd/config_flow.py
index 9ce29df02ea..ce9b0a13b18 100644
--- a/homeassistant/components/sabnzbd/config_flow.py
+++ b/homeassistant/components/sabnzbd/config_flow.py
@@ -64,6 +64,13 @@ class SABnzbdConfigFlow(ConfigFlow, domain=DOMAIN):
             if not sab_api:
                 errors["base"] = "cannot_connect"
             else:
+                self._async_abort_entries_match(
+                    {
+                        CONF_URL: user_input[CONF_URL],
+                        CONF_API_KEY: user_input[CONF_API_KEY],
+                    }
+                )
+
                 if self.source == SOURCE_RECONFIGURE:
                     return self.async_update_reload_and_abort(
                         self._get_reconfigure_entry(), data_updates=user_input
diff --git a/homeassistant/components/sabnzbd/strings.json b/homeassistant/components/sabnzbd/strings.json
index 78a8b88486e..186682e78e7 100644
--- a/homeassistant/components/sabnzbd/strings.json
+++ b/homeassistant/components/sabnzbd/strings.json
@@ -17,6 +17,7 @@
       "invalid_api_key": "[%key:common::config_flow::error::invalid_api_key%]"
     },
     "abort": {
+      "already_configured": "[%key:common::config_flow::abort::already_configured_service%]",
       "reconfigure_successful": "[%key:common::config_flow::abort::reconfigure_successful%]"
     }
   },
diff --git a/tests/components/sabnzbd/test_config_flow.py b/tests/components/sabnzbd/test_config_flow.py
index 8d8289e1e88..797af63c096 100644
--- a/tests/components/sabnzbd/test_config_flow.py
+++ b/tests/components/sabnzbd/test_config_flow.py
@@ -132,3 +132,38 @@ async def test_reconfigure_error(
         CONF_URL: "http://10.10.10.10:8080",
         CONF_API_KEY: "new_key",
     }
+
+
+async def test_abort_already_configured(
+    hass: HomeAssistant, config_entry: MockConfigEntry
+) -> None:
+    """Test that the flow aborts if SABnzbd instance is already configured."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN, context={"source": config_entries.SOURCE_USER}
+    )
+    assert result["type"] is FlowResultType.FORM
+    assert result["errors"] == {}
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        VALID_CONFIG,
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "already_configured"
+
+
+async def test_abort_reconfigure_already_configured(
+    hass: HomeAssistant, config_entry: MockConfigEntry
+) -> None:
+    """Test that the reconfigure flow aborts if SABnzbd instance is already configured."""
+    result = await config_entry.start_reconfigure_flow(hass)
+    assert result["type"] is FlowResultType.FORM
+    assert result["errors"] == {}
+
+    result = await hass.config_entries.flow.async_configure(
+        result["flow_id"],
+        VALID_CONFIG,
+    )
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "already_configured"