diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala
index 49303978d1ce8..d08a6382f738b 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/analysis/Analyzer.scala
@@ -2871,20 +2871,15 @@ class Analyzer(
         case udf: ScalaUDF if udf.inputEncoders.nonEmpty =>
           val boundEncoders = udf.inputEncoders.zipWithIndex.map { case (encOpt, i) =>
             val dataType = udf.children(i).dataType
-            if (dataType.existsRecursively(_.isInstanceOf[UserDefinedType[_]])) {
-              // for UDT, we use `CatalystTypeConverters`
-              None
-            } else {
-              encOpt.map { enc =>
-                val attrs = if (enc.isSerializedAsStructForTopLevel) {
-                  dataType.asInstanceOf[StructType].toAttributes
-                } else {
-                  // the field name doesn't matter here, so we use
-                  // a simple literal to avoid any overhead
-                  new StructType().add("input", dataType).toAttributes
-                }
-                enc.resolveAndBind(attrs)
+            encOpt.map { enc =>
+              val attrs = if (enc.isSerializedAsStructForTopLevel) {
+                dataType.asInstanceOf[StructType].toAttributes
+              } else {
+                // the field name doesn't matter here, so we use
+                // a simple literal to avoid any overhead
+                new StructType().add("input", dataType).toAttributes
               }
+              enc.resolveAndBind(attrs)
             }
           }
           udf.copy(inputEncoders = boundEncoders)
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Cast.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Cast.scala
index 3ce284d5518a8..e27c021556377 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Cast.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/Cast.scala
@@ -93,8 +93,7 @@ object Cast {
                 toField.nullable)
         }
 
-    case (udt1: UserDefinedType[_], udt2: UserDefinedType[_]) if udt1.userClass == udt2.userClass =>
-      true
+    case (udt1: UserDefinedType[_], udt2: UserDefinedType[_]) if udt2.acceptsType(udt1) => true
 
     case _ => false
   }
@@ -157,6 +156,8 @@ object Cast {
             resolvableNullability(f1.nullable, f2.nullable) && canUpCast(f1.dataType, f2.dataType)
         }
 
+    case (from: UserDefinedType[_], to: UserDefinedType[_]) if to.acceptsType(from) => true
+
     case _ => false
   }
 
@@ -810,8 +811,7 @@ abstract class CastBase extends UnaryExpression with TimeZoneAwareExpression wit
           castArray(from.asInstanceOf[ArrayType].elementType, array.elementType)
         case map: MapType => castMap(from.asInstanceOf[MapType], map)
         case struct: StructType => castStruct(from.asInstanceOf[StructType], struct)
-        case udt: UserDefinedType[_]
-          if udt.userClass == from.asInstanceOf[UserDefinedType[_]].userClass =>
+        case udt: UserDefinedType[_] if udt.acceptsType(from) =>
           identity[Any]
         case _: UserDefinedType[_] =>
           throw new SparkException(s"Cannot cast $from to $to.")
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ScalaUDF.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ScalaUDF.scala
index 1e3e6d90b8501..3d10b084a8db1 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ScalaUDF.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/ScalaUDF.scala
@@ -108,7 +108,6 @@ case class ScalaUDF(
    *   - UDF which doesn't provide inputEncoders, e.g., untyped Scala UDF and Java UDF
    *   - type which isn't supported by `ExpressionEncoder`, e.g., Any
    *   - primitive types, in order to use `identity` for better performance
-   *   - UserDefinedType which isn't fully supported by `ExpressionEncoder`
    * For other cases like case class, Option[T], we use `ExpressionEncoder` instead since
    * `CatalystTypeConverters` doesn't support these data types.
    *
@@ -121,8 +120,7 @@ case class ScalaUDF(
     val useEncoder =
       !(inputEncoders.isEmpty || // for untyped Scala UDF and Java UDF
       inputEncoders(i).isEmpty || // for types aren't supported by encoder, e.g. Any
-      inputPrimitives(i) || // for primitive types
-      dataType.existsRecursively(_.isInstanceOf[UserDefinedType[_]]))
+      inputPrimitives(i)) // for primitive types
 
     if (useEncoder) {
       val enc = inputEncoders(i).get
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala
index ed8ab1cb3a603..3fd5cc72cb95e 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/UserDefinedTypeSuite.scala
@@ -275,11 +275,11 @@ class UserDefinedTypeSuite extends QueryTest with SharedSparkSession with Parque
 
     // this worked already before the fix SPARK-19311:
     // return type of doUDF equals parameter type of doOtherUDF
-    sql("SELECT doOtherUDF(doUDF(41))")
+    checkAnswer(sql("SELECT doOtherUDF(doUDF(41))"), Row(41) :: Nil)
 
     // this one passes only with the fix SPARK-19311:
     // return type of doSubUDF is a subtype of the parameter type of doOtherUDF
-    sql("SELECT doOtherUDF(doSubTypeUDF(42))")
+    checkAnswer(sql("SELECT doOtherUDF(doSubTypeUDF(42))"), Row(42) :: Nil)
   }
 
   test("except on UDT") {