diff --git a/backend/src/graphql/resolver/TransactionResolver.test.ts b/backend/src/graphql/resolver/TransactionResolver.test.ts
index f4315d359..1d4fe5708 100644
--- a/backend/src/graphql/resolver/TransactionResolver.test.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.test.ts
@@ -291,7 +291,6 @@ describe('send coins', () => {
       await cleanDB()
     })
 
-    /*
     describe('trying to send negative amount', () => {
       it('throws an error', async () => {
         expect(
@@ -305,18 +304,15 @@ describe('send coins', () => {
           }),
         ).toEqual(
           expect.objectContaining({
-            errors: [new GraphQLError(`user hasn't enough GDD or amount is < 0`)],
+            errors: [new GraphQLError(`Amount to send must be positive`)],
           }),
         )
       })
 
       it('logs the error thrown', () => {
-        expect(logger.error).toBeCalledWith(
-          `user hasn't enough GDD or amount is < 0 : balance=null`,
-        )
+        expect(logger.error).toBeCalledWith(`Amount to send must be positive`)
       })
     })
-    */
 
     describe('good transaction', () => {
       it('sends the coins', async () => {
diff --git a/backend/src/graphql/resolver/TransactionResolver.ts b/backend/src/graphql/resolver/TransactionResolver.ts
index 594039cfd..3dbd4afb9 100644
--- a/backend/src/graphql/resolver/TransactionResolver.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.ts
@@ -314,6 +314,10 @@ export class TransactionResolver {
     @Ctx() context: Context,
   ): Promise<boolean> {
     logger.info(`sendCoins(email=${email}, amount=${amount}, memo=${memo})`)
+    if (amount.lte(0)) {
+      logger.error(`Amount to send must be positive`)
+      throw new Error('Amount to send must be positive')
+    }
 
     // TODO this is subject to replay attacks
     const senderUser = getUser(context)
@@ -324,22 +328,7 @@ export class TransactionResolver {
 
     // validate recipient user
     const recipientUser = await findUserByEmail(email)
-    /*
-    const emailContact = await UserContact.findOne({ email }, { withDeleted: true })
-    if (!emailContact) {
-      logger.error(`Could not find UserContact with email: ${email}`)
-      throw new Error(`Could not find UserContact with email: ${email}`)
-    }
-    */
-    // const recipientUser = await dbUser.findOne({ id: emailContact.userId })
 
-    /* Code inside this if statement is unreachable (useless by so), 
-    in findUserByEmail() an error is already thrown if the user is not found
-    */
-    if (!recipientUser) {
-      logger.error(`unknown recipient to UserContact: email=${email}`)
-      throw new Error('unknown recipient')
-    }
     if (recipientUser.deletedAt) {
       logger.error(`The recipient account was deleted: recipientUser=${recipientUser}`)
       throw new Error('The recipient account was deleted')