diff --git a/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/Book.java b/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/Book.java
index ad27bfb..500c09d 100644
--- a/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/Book.java
+++ b/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/Book.java
@@ -1,6 +1,7 @@
 package fr.iut_fbleau.but3.dev62.mylibrary.book.entity;
 
 
+import fr.iut_fbleau.but3.dev62.mylibrary.book.exception.IllegalBookStockException;
 import lombok.Builder;
 import lombok.Getter;
 
@@ -24,4 +25,11 @@ public class Book {
     public void addStock(Integer copyToAdd){
         this.stock += copyToAdd;
     }
+
+    public void removeStock(Integer copyToRemomve) throws IllegalBookStockException {
+        if (copyToRemomve > this.stock){
+            throw new IllegalBookStockException(copyToRemomve, this.stock);
+        }
+        this.stock -= copyToRemomve;
+    }
 }
diff --git a/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/exception/IllegalBookStockException.java b/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/exception/IllegalBookStockException.java
new file mode 100644
index 0000000..6d7db41
--- /dev/null
+++ b/src/main/java/fr/iut_fbleau/but3/dev62/mylibrary/book/exception/IllegalBookStockException.java
@@ -0,0 +1,13 @@
+package fr.iut_fbleau.but3.dev62.mylibrary.book.exception;
+
+import java.text.MessageFormat;
+
+public class IllegalBookStockException extends Exception {
+    public static final String CANNOT_REMOVE_COPY = "Cannot remove {0} copy from {1} copy";
+
+    public IllegalBookStockException(Integer toremove, Integer actual ) {
+
+        super(MessageFormat.format(CANNOT_REMOVE_COPY, toremove,
+                actual));
+    }
+}
diff --git a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/BookTest.java b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/BookTest.java
index db21e1d..14fe7da 100644
--- a/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/BookTest.java
+++ b/src/test/java/fr/iut_fbleau/but3/dev62/mylibrary/book/entity/BookTest.java
@@ -1,7 +1,7 @@
 package fr.iut_fbleau.but3.dev62.mylibrary.book.entity;
 
-import fr.iut_fbleau.but3.dev62.mylibrary.book.BookDTO;
-import fr.iut_fbleau.but3.dev62.mylibrary.book.converter.BookConverter;
+
+import fr.iut_fbleau.but3.dev62.mylibrary.book.exception.IllegalBookStockException;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Nested;
 import org.junit.jupiter.api.Test;
@@ -9,7 +9,8 @@ import org.junit.jupiter.api.Test;
 import java.time.LocalDate;
 import java.util.ArrayList;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public class BookTest {
 
@@ -84,5 +85,66 @@ public class BookTest {
 
             assertEquals(copyExpected, book.getStock());
         }
+
+        @Test
+        @DisplayName("removeLoyaltyPoints should correctly decrement loyalty points")
+        void testRemoveCopy() throws IllegalBookStockException {
+            Book book =Book.builder()
+                    .stock(5)
+                    .build();
+            Integer copyToRemove = 2;
+            Integer copyExpected = 3;
+
+            book.removeStock(copyToRemove);
+
+            assertEquals(copyExpected, book.getStock());
+        }
+
+        @Test
+        @DisplayName("removeLoyaltyPoints should correctly decrement loyalty points")
+        void testRemoveZeroToCopy() throws IllegalBookStockException {
+            Book book =Book.builder()
+                    .stock(5)
+                    .build();
+            Integer copyToRemove = 0;
+            Integer copyExpected = 5;
+
+            book.removeStock(copyToRemove);
+
+            assertEquals(copyExpected, book.getStock());
+        }
+
+        @Test
+        @DisplayName("removeLoyaltyPoints should correctly decrement loyalty points")
+        void testRemoveAllToCopy() throws IllegalBookStockException {
+            Book book =Book.builder()
+                    .stock(5)
+                    .build();
+            Integer copyToRemove = 5;
+            Integer copyExpected = 0;
+
+            book.removeStock(copyToRemove);
+
+            assertEquals(copyExpected, book.getStock());
+        }
+
+        @Test
+        @DisplayName("removeSTock should throw exception when trying to remove more copy than available")
+        void testRemoveTooManyCopy() {
+            Book book = Book.builder()
+                    .stock(50)
+                    .build();
+            int copyToRemove = 75;
+
+            IllegalBookStockException exception = assertThrows(
+                    IllegalBookStockException.class,
+                    () -> book.removeStock(copyToRemove)
+            );
+
+            assertEquals(50, book.getStock());
+
+            assertTrue(exception.getMessage().contains(String.valueOf(copyToRemove)));
+            assertTrue(exception.getMessage().contains(String.valueOf(book.getStock())));
+        }
     }
 }