diff --git a/homeassistant/components/sma/config_flow.py b/homeassistant/components/sma/config_flow.py
index c648ec903cd4..321fb2812e51 100644
--- a/homeassistant/components/sma/config_flow.py
+++ b/homeassistant/components/sma/config_flow.py
@@ -3,6 +3,7 @@
 from collections.abc import Mapping
 import dataclasses
 import logging
+import re
 from typing import Any, override
 
 import probatio
@@ -38,6 +39,9 @@ from .const import CONF_GROUP, DOMAIN, GROUPS
 
 _LOGGER = logging.getLogger(__name__)
 
+# Example hostnames: sma3015638141, sma3015598606-2856
+HOSTNAME_SERIAL = re.compile(r"^sma-?(\d+)(?:-|$)", re.IGNORECASE)
+
 
 STEP_USER_DATA_SCHEMA = probatio.Schema(
     {
@@ -291,15 +295,9 @@ class SmaConfigFlow(ConfigFlow, domain=DOMAIN):
                 entry, data_updates={CONF_MAC: self._data[CONF_MAC]}
             )
 
-        # Finally, check if the hostname
-        # (which represents the SMA serial number) is unique
-        serial_number = discovery_info.hostname.lower()
-        # Example hostname: sma12345678-01
-        # Remove 'sma' prefix and strip everything after the dash (including the dash)
-        if serial_number.startswith("sma"):
-            serial_number = serial_number.removeprefix("sma")
-        serial_number = serial_number.split("-", 1)[0]
-        await self.async_set_unique_id(serial_number)
+        if not (match := HOSTNAME_SERIAL.match(discovery_info.hostname)):
+            return self.async_abort(reason="not_supported")
+        await self.async_set_unique_id(match.group(1))
         self._abort_if_unique_id_configured()
 
         return await self.async_step_discovery_confirm()
diff --git a/homeassistant/components/sma/strings.json b/homeassistant/components/sma/strings.json
index 482e9375a072..4e16f3b635a3 100644
--- a/homeassistant/components/sma/strings.json
+++ b/homeassistant/components/sma/strings.json
@@ -2,6 +2,7 @@
   "config": {
     "abort": {
       "already_configured": "[%key:common::config_flow::abort::already_configured_device%]",
+      "not_supported": "This SMA device is not supported",
       "unique_id_mismatch": "You selected a different SMA device than the one this config entry was configured with, this is not allowed."
     },
     "error": {
diff --git a/tests/components/sma/test_config_flow.py b/tests/components/sma/test_config_flow.py
index 9ccb90abb610..2d362da92843 100644
--- a/tests/components/sma/test_config_flow.py
+++ b/tests/components/sma/test_config_flow.py
@@ -222,6 +222,56 @@ async def test_dhcp_already_configured_duplicate(
     )
 
 
+@pytest.mark.parametrize(
+    ("hostname", "unique_id"),
+    [
+        pytest.param("SMA123456789", "123456789", id="serial"),
+        pytest.param("SMA-123456789", "123456789", id="dash_serial"),
+        pytest.param("sma123456789-2856", "123456789", id="serial_suffix"),
+    ],
+)
+@pytest.mark.usefixtures("mock_setup_entry")
+async def test_dhcp_hostname_serial(
+    hass: HomeAssistant, hostname: str, unique_id: str
+) -> None:
+    """Test the serial number is read from the DHCP hostname."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={"source": SOURCE_DHCP},
+        data=DhcpServiceInfo(
+            ip="1.1.1.2", hostname=hostname, macaddress="0015bb00abcd"
+        ),
+    )
+
+    assert result["type"] is FlowResultType.FORM
+    assert result["step_id"] == "discovery_confirm"
+    flow = hass.config_entries.flow.async_get(result["flow_id"])
+    assert flow["context"]["unique_id"] == unique_id
+
+
+@pytest.mark.parametrize(
+    "hostname",
+    [
+        pytest.param("SMA", id="prefix_only"),
+        pytest.param("SMA-EVCharger", id="name"),
+        pytest.param("smaevc22", id="no_serial"),
+        pytest.param("sma12abc", id="partial_serial"),
+    ],
+)
+async def test_dhcp_not_supported(hass: HomeAssistant, hostname: str) -> None:
+    """Test DHCP discovery aborts for hostnames without a serial number."""
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={"source": SOURCE_DHCP},
+        data=DhcpServiceInfo(
+            ip="1.1.1.2", hostname=hostname, macaddress="0015bb00abcd"
+        ),
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "not_supported"
+
+
 @pytest.mark.parametrize(
     ("exception", "error"),
     [