diff --git a/src/api/parsers.py b/src/api/parsers.py
index 31a36bb0..28b1da79 100644
--- a/src/api/parsers.py
+++ b/src/api/parsers.py
@@ -46,12 +46,7 @@ def parse_name(name: str) -> str:
             else:
                 parsed_name += char
         elif char.isdigit():
-            num_digits = 0
-            for c in name:  # greedily retrieve as many digits as possible
-                if c.isdigit():
-                    num_digits += 1
-                else:
-                    break
+            num_digits = _greedily_count_digits_at_start_of_str(name)
             word = Helpers.number_to_word(int(name[:num_digits]))
             if parsed_name != "":
                 word = Helpers.capitalize(word)
@@ -75,6 +70,17 @@ def parse_name(name: str) -> str:
     return parsed_name
 
 
+def _greedily_count_digits_at_start_of_str(word: str) -> int:
+    """Counts the number of digits at the start of the string."""
+    num_digits = 0
+    for c in word:
+        if c.isdigit():
+            num_digits += 1
+        else:
+            break
+    return num_digits
+
+
 def parse_unit(unit: str) -> str:
     """Parses the unit."""
     if not isinstance(unit, str):
diff --git a/tests/parsers_test.py b/tests/parsers_test.py
new file mode 100644
index 00000000..aaf1fc07
--- /dev/null
+++ b/tests/parsers_test.py
@@ -0,0 +1,39 @@
+import pytest
+
+from api import parsers
+
+
+class TestNameParser:
+
+    @pytest.mark.parametrize(
+        "name, expected",
+        [
+            ("a12", "aTwelve"),
+            ("a01", "aOne"),
+            ("042", "fortyTwo"),
+            ("a911bc13", "aNineHundredElevenBcThirteen"),
+            ("13_600", "thirteenSixHundred"),
+            ("a_5_6b7_$5", "aFiveSixBSevenFive"),
+        ],
+    )
+    def test_number_substitution(self, name: str, expected: str):
+        assert parsers.parse_name(name) == expected
+
+    @pytest.mark.parametrize(
+        "name, expected",
+        [
+            ("ä", "ae"),
+            ("Ä", "Ae"),
+            ("ü", "ue"),
+            ("Ü", "Ue"),
+            ("ö", "oe"),
+            ("Ö", "Oe"),
+            ("ß", "ss"),
+            ("ẞ", "Ss"),
+            ("äh", "aeh"),
+            ("Füße", "Fuesse"),
+            ("GIEẞEN", "GIESsEN"),
+        ],
+    )
+    def test_umlaut_replacement(self, name: str, expected: str):
+        assert parsers.parse_name(name) == expected