diff --git a/common/hyperscaler/rules/grammar/listener.go b/common/hyperscaler/rules/grammar/listener.go
index f2f7fe499e..be321955c7 100644
--- a/common/hyperscaler/rules/grammar/listener.go
+++ b/common/hyperscaler/rules/grammar/listener.go
@@ -12,21 +12,31 @@ type RuleListener struct {
 }
 
 func (r RuleListener) EnterEntry(c *parser.EntryContext) {
-    r.processed.Plan = c.PLAN().GetText()
+	if c.PLAN() != nil {
+		r.processed.Plan = c.PLAN().GetText()
+	}
 }
 
 func (r *RuleListener) EnterPrVal(c *parser.PrValContext) {
-	r.processed.PlatformRegion = c.Val().GetText()
+	if c.Val() != nil {
+		r.processed.PlatformRegion = c.Val().GetText()
+	}
 }
 
 func (r *RuleListener) EnterHrVal(c *parser.HrValContext) {
-	r.processed.HyperscalerRegion = c.Val().GetText()
+	if c.Val() != nil {
+		r.processed.HyperscalerRegion = c.Val().GetText()
+	}
 }
 
 func (s *RuleListener) EnterS(c *parser.SContext) {
-	s.processed.Shared = true
+	if c.S() != nil {
+		s.processed.Shared = true
+	}
 }
 
 func (s *RuleListener) EnterEu(c *parser.EuContext) {
-	s.processed.EuAccess = true
+	if c.EU() != nil {
+		s.processed.EuAccess = true
+	}
 }
diff --git a/common/hyperscaler/rules/grammar/parser.go b/common/hyperscaler/rules/grammar/parser.go
index 9a2f5aa3b3..6ff1c02cf8 100644
--- a/common/hyperscaler/rules/grammar/parser.go
+++ b/common/hyperscaler/rules/grammar/parser.go
@@ -7,24 +7,54 @@ import (
 )
 
 type GrammarParser struct{
-    
 }
 
-func (g* GrammarParser) Parse(ruleEntry string) *rules.Rule {
-		// Setup the input
+func (g* GrammarParser) Parse(ruleEntry string) (*rules.Rule, error) {
 		is := antlr.NewInputStream(ruleEntry)
 
-		// Create the Lexer
+		erorrsListener := &ErrorListener{}
+
 		lexer := parser.NewRuleLexer(is)
+		lexer.RemoveErrorListeners()
+		lexer.AddErrorListener(erorrsListener)
+
 		stream := antlr.NewCommonTokenStream(lexer, antlr.TokenDefaultChannel)
 
-		// Create the Parser
 		p := parser.NewRuleParserParser(stream)
+	
+		p.RemoveErrorListeners()
+		p.AddErrorListener(erorrsListener)
 
-		// Finally parse the expression
         listener := &RuleListener{processed: &rules.Rule{}}
 		antlr.ParseTreeWalkerDefault.Walk(listener, p.RuleEntry())
-        return listener.processed
+
+		if len(erorrsListener.Errors) > 0 {
+			return nil, erorrsListener.Errors[0]
+		}
+
+        return listener.processed, nil
+}
+
+type SyntaxError struct {
+    line, column int
+    msg          string
+}
+
+func (c *SyntaxError) Error() string {
+	return c.msg
+}
+
+type ErrorListener struct {
+    *antlr.DefaultErrorListener
+    Errors []error
+}
+
+func (c *ErrorListener) SyntaxError(recognizer antlr.Recognizer, offendingSymbol interface{}, line, column int, msg string, e antlr.RecognitionException) {
+    c.Errors = append(c.Errors, &SyntaxError{
+        line:   line,
+        column: column,
+        msg:    msg,
+    })
 }
 
 
diff --git a/common/hyperscaler/rules/grammar/parser_test.go b/common/hyperscaler/rules/grammar/parser_test.go
index 0a4209b559..25dba32d58 100644
--- a/common/hyperscaler/rules/grammar/parser_test.go
+++ b/common/hyperscaler/rules/grammar/parser_test.go
@@ -5,7 +5,6 @@ import "testing"
 import "github.com/kyma-project/kyma-environment-broker/common/hyperscaler/rules"
 
 func TestParser(t *testing.T) {
-
-    rules.ParserTest(t, &GrammarParser{})
-    
+    rules.ParserHappyPathTest(t, &GrammarParser{})
+    rules.ParserValidationTest(t, &GrammarParser{})
 }
\ No newline at end of file
diff --git a/common/hyperscaler/rules/parser.go b/common/hyperscaler/rules/parser.go
index 8780a9beb1..c4a44fbee8 100644
--- a/common/hyperscaler/rules/parser.go
+++ b/common/hyperscaler/rules/parser.go
@@ -1,5 +1,5 @@
 package rules
 
 type Parser interface {
-    Parse(ruleEntry string) *Rule
+    Parse(ruleEntry string) (*Rule, error)
 }
\ No newline at end of file
diff --git a/common/hyperscaler/rules/parser_test_utils.go b/common/hyperscaler/rules/parser_test_utils.go
index 18298a5766..414fb55850 100644
--- a/common/hyperscaler/rules/parser_test_utils.go
+++ b/common/hyperscaler/rules/parser_test_utils.go
@@ -6,10 +6,11 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func ParserTest(t *testing.T, parser Parser) {
+func ParserHappyPathTest(t *testing.T, parser Parser) {
 
     t.Run("with plan", func(t *testing.T) {
-        rule := parser.Parse("azure")
+        rule, err := parser.Parse("azure")
+        require.NoError(t, err)
 
         require.NotNil(t, rule)
         require.Equal(t, "azure", rule.Plan)
@@ -20,8 +21,9 @@ func ParserTest(t *testing.T, parser Parser) {
         require.Equal(t, false, rule.Shared)
     })
 
-    t.Run("with plan and platform region", func(t *testing.T) {
-        rule := parser.Parse("azure(PR=westeurope)")
+    t.Run("with plan and single input attribute", func(t *testing.T) {
+        rule, err := parser.Parse("azure(PR=westeurope)")
+        require.NoError(t, err)
 
         require.NotNil(t, rule)
         require.Equal(t, "azure", rule.Plan)
@@ -30,10 +32,9 @@ func ParserTest(t *testing.T, parser Parser) {
 
         require.Equal(t, false, rule.EuAccess)
         require.Equal(t, false, rule.Shared)
-    })
 
-    t.Run("with plan and hyperscaler region", func(t *testing.T) {
-        rule := parser.Parse("azure(HR=westeurope)")
+        rule, err = parser.Parse("azure(HR=westeurope)")
+        require.NoError(t, err)
 
         require.NotNil(t, rule)
         require.Equal(t, "azure", rule.Plan)
@@ -44,8 +45,20 @@ func ParserTest(t *testing.T, parser Parser) {
         require.Equal(t, false, rule.Shared)
     })
 
-    t.Run("with plan, platform and hyperscaler region", func(t *testing.T) {
-        rule := parser.Parse("azure(PR=easteurope, HR=westeurope)")
+    t.Run("with plan all output attributes - different positions", func(t *testing.T) {
+        rule, err := parser.Parse("azure(PR=easteurope,HR=westeurope)")
+        require.NoError(t, err)
+
+        require.NotNil(t, rule)
+        require.Equal(t, "azure", rule.Plan)
+        require.Equal(t, "westeurope", rule.HyperscalerRegion)
+        require.Equal(t, "easteurope", rule.PlatformRegion)
+
+        require.False(t, rule.EuAccess)
+        require.False(t, rule.Shared)
+
+        rule, err = parser.Parse("azure(HR=westeurope,PR=easteurope)")
+        require.NoError(t, err)
 
         require.NotNil(t, rule)
         require.Equal(t, "azure", rule.Plan)
@@ -56,8 +69,9 @@ func ParserTest(t *testing.T, parser Parser) {
         require.False(t, rule.Shared)
     })
 
-    t.Run("with plan and shared", func(t *testing.T) {
-        rule := parser.Parse("azure->S")
+    t.Run("with plan and single output attribute", func(t *testing.T) {
+        rule, err := parser.Parse("azure->S")
+        require.NoError(t, err)
 
         require.NotNil(t, rule)
         require.Equal(t, "azure", rule.Plan)
@@ -66,11 +80,23 @@ func ParserTest(t *testing.T, parser Parser) {
 
         require.False(t, rule.EuAccess)
         require.True(t, rule.Shared)
+
+        rule, err = parser.Parse("azure->EU")
+        require.NoError(t, err)
+
+        require.NotNil(t, rule)
+        require.Equal(t, "azure", rule.Plan)
+        require.Empty(t, rule.HyperscalerRegion)
+        require.Empty(t, rule.PlatformRegion)
+
+        require.True(t, rule.EuAccess)
+        require.False(t, rule.Shared)
     })
 
 
-    t.Run("with plan, shared and euAccess", func(t *testing.T) {
-        rule := parser.Parse("azure->S,EU")
+    t.Run("with plan and all output attributes - different positions", func(t *testing.T) {
+        rule, err := parser.Parse("azure->S,EU")
+        require.NoError(t, err)
 
         require.NotNil(t, rule)
         require.Equal(t, "azure", rule.Plan)
@@ -79,6 +105,78 @@ func ParserTest(t *testing.T, parser Parser) {
 
         require.True(t, rule.EuAccess)
         require.True(t, rule.Shared)
+
+        rule, err = parser.Parse("azure->EU,S")
+        require.NoError(t, err)
+
+        require.NotNil(t, rule)
+        require.Equal(t, "azure", rule.Plan)
+        require.Empty(t, rule.HyperscalerRegion)
+        require.Empty(t, rule.PlatformRegion)
+
+        require.True(t, rule.EuAccess)
+        require.True(t, rule.Shared)
+    })
+
+    t.Run("with plan and single output/input attributes", func(t *testing.T) {
+        rule, err := parser.Parse("azure(PR=westeurope)->EU")
+        require.NoError(t, err)
+
+        require.NotNil(t, rule)
+        require.Equal(t, "azure", rule.Plan)
+        require.Empty(t, rule.HyperscalerRegion)
+        require.Equal(t, "westeurope", rule.PlatformRegion)
+
+        require.True(t, rule.EuAccess)
+        require.False(t, rule.Shared)
+    }) 
+
+    t.Run("with plan and all input/output attributes", func(t *testing.T) {
+        rule, err := parser.Parse("azure(PR=westeurope, HR=easteurope)->EU,S")
+        require.NoError(t, err)
+
+        require.NotNil(t, rule)
+        require.Equal(t, "azure", rule.Plan)
+        require.Equal(t, "easteurope", rule.HyperscalerRegion)
+        require.Equal(t, "westeurope", rule.PlatformRegion)
+
+        require.True(t, rule.EuAccess)
+        require.True(t, rule.Shared)
+    }) 
+}
+
+
+func ParserValidationTest(t *testing.T, parser Parser) {
+
+    t.Run("with paranthesis only", func(t *testing.T) {
+        rule, err := parser.Parse("()")
+        require.Nil(t, rule)
+        require.Error(t, err)
+    })
+
+    t.Run("with arrow only", func(t *testing.T) {
+        rule, err := parser.Parse("->")
+        require.Nil(t, rule)
+        require.Error(t, err)
+    })
+
+    t.Run("with incorrect attributes list", func(t *testing.T) {
+        rule, err := parser.Parse("test(,)->,")
+        require.Nil(t, rule)
+        require.Error(t, err)
+    
+        rule, err = parser.Parse("test(PR=west,HR=east)->,")
+        require.Nil(t, rule)
+        require.Error(t, err)
     })
 
+//     t.Run("with duplicated input attribute", func(t *testing.T) {
+//         rule, err := parser.Parse("azure(PR=test,PR=test2)")
+//         require.Nil(t, rule)
+//         require.Error(t, err)
+    
+//         rule, err = parser.Parse("test(PR=west,HR=east)->EU,EU")
+//         require.Nil(t, rule)
+//         require.Error(t, err)
+//     })
 }
\ No newline at end of file
diff --git a/common/hyperscaler/rules/simple_parser.go b/common/hyperscaler/rules/simple_parser.go
index 170278019c..427b4d62f6 100644
--- a/common/hyperscaler/rules/simple_parser.go
+++ b/common/hyperscaler/rules/simple_parser.go
@@ -1,6 +1,7 @@
 package rules
 
 import (
+	"fmt"
 	"strings"
 )
 
@@ -8,7 +9,7 @@ type SimpleParser struct{
     
 }
 
-func (g* SimpleParser) Parse(ruleEntry string) *Rule {
+func (g* SimpleParser) Parse(ruleEntry string) (*Rule, error) {
     outputRule := &Rule{}
 
     outputInputPart := strings.Split(ruleEntry, "->")
@@ -18,6 +19,9 @@ func (g* SimpleParser) Parse(ruleEntry string) *Rule {
     planAndInputAttr := strings.Split(inputPart, "(")
 
     outputRule.Plan = planAndInputAttr[0]
+    if outputRule.Plan == "" {
+        return nil, fmt.Errorf("plan is empty")
+    }
 
     if len(planAndInputAttr) > 1 {
         inputPart := strings.TrimSuffix(planAndInputAttr[1], ")")
@@ -25,6 +29,11 @@ func (g* SimpleParser) Parse(ruleEntry string) *Rule {
         inputAttrs := strings.Split(inputPart, ",")
 
         for _, inputAttr := range inputAttrs {
+
+            if inputAttr == "" {
+                return nil, fmt.Errorf("input attribute is empty")
+            }
+
             if strings.Contains(inputAttr, "PR") {
                 outputRule.PlatformRegion = strings.Split(inputAttr, "=")[1]
             }
@@ -33,13 +42,16 @@ func (g* SimpleParser) Parse(ruleEntry string) *Rule {
                 outputRule.HyperscalerRegion = strings.Split(inputAttr, "=")[1]
             }
         }
-
     }
 
     if len(outputInputPart) > 1 {
         outputAttrs := strings.Split(outputInputPart[1], ",")
     
         for _, outputAttr := range outputAttrs {
+            if outputAttr == "" {
+                return nil, fmt.Errorf("output attribute is empty")
+            }
+
             if outputAttr == "S" {
                 outputRule.Shared = true
             } else if outputAttr == "EU" {
@@ -48,5 +60,5 @@ func (g* SimpleParser) Parse(ruleEntry string) *Rule {
         }
     }
 
-    return outputRule
+    return outputRule, nil
 }
diff --git a/common/hyperscaler/rules/simple_parser_test.go b/common/hyperscaler/rules/simple_parser_test.go
index 821f72d3a7..6dcfa85940 100644
--- a/common/hyperscaler/rules/simple_parser_test.go
+++ b/common/hyperscaler/rules/simple_parser_test.go
@@ -3,7 +3,6 @@ package rules
 import "testing"
 
 func TestParser(t *testing.T) {
-
-    ParserTest(t, &SimpleParser{})
-    
+    ParserHappyPathTest(t, &SimpleParser{})
+    ParserValidationTest(t, &SimpleParser{})
 }
\ No newline at end of file