diff --git a/src/request.js b/src/request.js
index f20d9e2..fc05884 100644
--- a/src/request.js
+++ b/src/request.js
@@ -9,6 +9,7 @@ class Request {
   // Account
 
   accountSetup(key, secret, flags) {
+    key = key.toLowerCase();
     this._verifyCredentials(key, secret, this.response.accountSetup(this.config, key, secret, flags).bind(this.response));
   }
 
diff --git a/tests/request.js b/tests/request.js
index c3b09df..50614e0 100644
--- a/tests/request.js
+++ b/tests/request.js
@@ -36,15 +36,24 @@ describe('Request', () => {
     });
 
     describe('.accountSetup', () => {
-      it('should verifiy the credentials', sinon.test(function(){
+      beforeEach(() => {
         nexmo = {};
         nexmo.account = sinon.createStubInstance(Account);
         client.instanceWith.returns(nexmo);
         response.accountSetup.returns(()=>{});
+      });
+
+      it('should verify the credentials', sinon.test(function(){
         request.accountSetup('123', 'abc', false);
         expect(nexmo.account.checkBalance).to.have.been.called;
         expect(response.accountSetup).to.have.been.called;
       }));
+
+      it('should convert API key to lower case', sinon.test(function(){
+        request.accountSetup('ABC123', 'abc', false);
+        expect(nexmo.account.checkBalance).to.have.been.called;
+        expect(response.accountSetup).to.have.been.calledWith(config, 'abc123', 'abc', false);
+      }));
     });
 
     describe('.accountInfo', () => {