diff --git a/src/main/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidator.java b/src/main/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidator.java
index 43d4f1f..0895d92 100644
--- a/src/main/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidator.java
+++ b/src/main/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidator.java
@@ -4,12 +4,21 @@ import eu.ztsh.wymiana.web.model.CurrencyExchangeRequest;
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
 
-public class ValidExchangeRequestValidator implements ConstraintValidator<ValidExchangeRequest, CurrencyExchangeRequest> {
+public class ValidExchangeRequestValidator implements
+    ConstraintValidator<ValidExchangeRequest, CurrencyExchangeRequest> {
 
     @Override
-    public boolean isValid(CurrencyExchangeRequest currencyExchangeRequest,
+    public boolean isValid(CurrencyExchangeRequest request,
                            ConstraintValidatorContext constraintValidatorContext) {
-        return false;
+        if (request == null) {
+            return false;
+        }
+
+        return !request.from().equals(request.to())
+            && !((request.toBuy() == null && request.toSell() == null)
+                || (request.toBuy() != null && request.toSell() != null))
+            && ((request.toBuy() != null && request.toBuy() >= 0)
+                || (request.toSell() != null && request.toSell() >= 0));
     }
 
 }
diff --git a/src/test/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidatorTest.java b/src/test/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidatorTest.java
index 0e6ebb8..85161e6 100644
--- a/src/test/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidatorTest.java
+++ b/src/test/java/eu/ztsh/wymiana/validation/ValidExchangeRequestValidatorTest.java
@@ -2,8 +2,13 @@ package eu.ztsh.wymiana.validation;
 
 import eu.ztsh.wymiana.EntityCreator;
 import eu.ztsh.wymiana.web.model.CurrencyExchangeRequest;
+import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import java.util.stream.Stream;
 
 import static eu.ztsh.wymiana.EntityCreator.Constants.*;
 
@@ -33,17 +38,13 @@ class ValidExchangeRequestValidatorTest extends ValidatorTest<ValidExchangeReque
             .build()).isTrue();
     }
 
-    @Test
+    @Disabled("Already validated (has field annotation)")
     @DisplayName("Invalid PESEL value")
-    void invalidPeselTest() {
+    @ParameterizedTest
+    @MethodSource
+    void invalidPeselTest(String pesel) {
         assertThatValidation(EntityCreator.exchangeRequest()
-            .pesel("INVALID")
-            .from(PLN_SYMBOL)
-            .to(USD_SYMBOL)
-            .toSell(USD_SELL)
-            .build()).isFalse();
-        assertThatValidation(EntityCreator.exchangeRequest()
-            .pesel(PESEL.replace('6', '7'))
+            .pesel(pesel)
             .from(PLN_SYMBOL)
             .to(USD_SYMBOL)
             .toSell(USD_SELL)
@@ -69,6 +70,26 @@ class ValidExchangeRequestValidatorTest extends ValidatorTest<ValidExchangeReque
             .build()).isFalse();
     }
 
+    @Disabled("Already validated (has field annotation)")
+    @Test
+    @DisplayName("Empty 'from' value")
+    void emptyFromTest() {
+        assertThatValidation(EntityCreator.exchangeRequest()
+            .to(USD_SYMBOL)
+            .toSell(USD_SELL)
+            .build()).isFalse();
+    }
+
+    @Disabled("Already validated (has field annotation)")
+    @Test
+    @DisplayName("Empty 'to' value")
+    void emptyToTest() {
+        assertThatValidation(EntityCreator.exchangeRequest()
+            .from(PLN_SYMBOL)
+            .toSell(USD_SELL)
+            .build()).isFalse();
+    }
+
     @Test
     @DisplayName("Both Buy and Sell params filled in")
     void bothFilledBuySellTest() {
@@ -100,4 +121,8 @@ class ValidExchangeRequestValidatorTest extends ValidatorTest<ValidExchangeReque
             .build()).isFalse();
     }
 
+    private static Stream<String> invalidPeselTest() {
+        return Stream.of("INVALID", PESEL.replace('6', '7'));
+    }
+
 }