diff --git a/src/database/AcebaseClient.ts b/src/database/AcebaseClient.ts
index b91c4c8..731277b 100644
--- a/src/database/AcebaseClient.ts
+++ b/src/database/AcebaseClient.ts
@@ -61,6 +61,10 @@ export class AceBaseClient implements Database {
     }
 
     async addOrder(indexedOrder: IndexedOrder<DbOrder>): Promise<void> {
+        await this.refOrders.query()
+            .filter('order/signer/wallet', '==', indexedOrder.order.signer.wallet)
+            .filter('order/signer/id', '==', indexedOrder.order.signer.id)
+            .remove();
         await this.refOrders.push(indexedOrder);
         this.addToken(indexedOrder.order.signer.token)
         this.addToken(indexedOrder.order.sender.token)
diff --git a/src/database/InMemoryDatabase.ts b/src/database/InMemoryDatabase.ts
index 072d36f..435bfba 100644
--- a/src/database/InMemoryDatabase.ts
+++ b/src/database/InMemoryDatabase.ts
@@ -179,7 +179,12 @@ export class InMemoryDatabase implements Database {
   }
 
   ////////////////////////////// Non ERC20
-  addOrder(indexedOrder: IndexedOrder<DbOrder>): Promise<void> {
+  async addOrder(indexedOrder: IndexedOrder<DbOrder>): Promise<void> {
+    const ordersToDelete = await this.findOrders((order: DbOrder) => {
+      return order.signer.wallet === indexedOrder.order.signer.wallet && order.signer.id === indexedOrder.order.signer.id
+    })
+    this.deleteOrders(ordersToDelete)
+
     this.orderDatabase[indexedOrder.hash!] = indexedOrder;
     this.addToken(indexedOrder.order.signer.token)
     this.addToken(indexedOrder.order.sender.token)
@@ -193,17 +198,32 @@ export class InMemoryDatabase implements Database {
     return Promise.resolve();
   }
 
-  deleteOrder(nonce: number, signerWallet: string): Promise<void> {
-    const orderToDelete = Object.values(this.orderDatabase).find((indexedOrder) => {
-      const order = indexedOrder.order as DbOrder
+  async deleteOrder(nonce: number, signerWallet: string): Promise<void> {
+    const ordersToDelete = await this.findOrders((order: DbOrder) => {
       return order.nonce === nonce && order.signer.wallet === signerWallet
-    });
-    if (orderToDelete && orderToDelete.hash) {
-      delete this.orderDatabase[orderToDelete.hash];
-    }
+    })
+    this.deleteOrders(ordersToDelete)
     return Promise.resolve();
   }
 
+  private deleteOrders(orders: IndexedOrder<DbOrder>[]) {
+    if (orders && orders.length > 0) {
+      orders.forEach(orderDb => {
+        if (orderDb.hash) {
+          delete this.orderDatabase[orderDb.hash];
+        }
+      })
+    }
+  }
+
+  private findOrders(predicate: Function): Promise<IndexedOrder<DbOrder>[]> {
+    const orders = Object.values(this.orderDatabase).filter((indexedOrder) => {
+      const order = indexedOrder.order as DbOrder
+      return predicate(order)
+    });
+    return Promise.resolve(orders);
+  }
+
   deleteExpiredOrder(timestampInSeconds: number): Promise<void> {
     const hashToDelete: string[] = Object.keys(this.orderDatabase).filter((key: string) => {
       return this.orderDatabase[key].order.expiry < timestampInSeconds;
diff --git a/src/database/__tests__/Database.test.ts b/src/database/__tests__/Database.test.ts
index 0a6b345..1ebd4a5 100644
--- a/src/database/__tests__/Database.test.ts
+++ b/src/database/__tests__/Database.test.ts
@@ -150,6 +150,13 @@ describe("Database implementations", () => {
         })
     });
 
+    describe("Specific Order", () => {
+        describe("pair signerwallet-tokenId should be unique", () => {
+            test("inMemoryDb", async () => { await pairSignerwalletTokenIDIsUnique(inMemoryDatabase); });
+            test("acebaseDb", async () => { await pairSignerwalletTokenIDIsUnique(acebaseClient); });
+        })
+    });
+
     async function getOrdersERC20By(db: Database) {
         const dbOrder1: DbOrderERC20 = {
             nonce: 123,
@@ -841,4 +848,29 @@ describe("Database implementations", () => {
         expect(hash).toBe("86903491dd10421ee4bc866341c9852e18b296d429ed1fdc9fc9c30701d6d8cd");
         return Promise.resolve();
     }
+
+    async function pairSignerwalletTokenIDIsUnique(db: Database) {
+        const indexedOrderToOverwrite = forgeIndexedOrder(addedOn, expiryDate, "a_hash");
+        const indexedOrder = forgeIndexedOrder(addedOn, expiryDate, "another_hash");
+        indexedOrder.order.signer.amount = "100000003"
+        const expectedIndexedOrder = forgeIndexedOrderResponse(addedOn, expiryDate, "another_hash");
+        expectedIndexedOrder.order.signer.amount = "100000003"
+
+        await db.addOrder(indexedOrderToOverwrite);
+        await db.addOrder(indexedOrder);
+
+        const removedOrder = await db.getOrder("a_hash");
+        const existingOrder = await db.getOrder("another_hash");
+
+        expect(removedOrder.pagination.total).toBe(0)
+        expect(existingOrder).toEqual({
+            orders: { another_hash: expectedIndexedOrder },
+            pagination: {
+                limit: 1,
+                offset: 0,
+                total: 1,
+            },
+        });
+        return Promise.resolve();
+    }
 });
\ No newline at end of file