diff --git a/README.md b/README.md
index b29ac48..82f21d3 100644
--- a/README.md
+++ b/README.md
@@ -68,6 +68,7 @@ whmcs_client.customers.getCustomerEmails(clientid, function(err, emails) {
 - cancelOrder: function (orderid, callback)
 - deleteOrder: function (orderid, callback)
 - createInvoice: function (clientid, invoice, callback)
+- capturePayment: function (invoiceid, options, callback)
 
 ### Customers
 
@@ -95,6 +96,7 @@ whmcs_client.customers.getCustomerEmails(clientid, function(err, emails) {
 - getProducts: function (gid, callback)
 - getProductsByType: function (type, id, callback)
 - getOrders: function (method, id, offset, limit, callback)
+- upgradeProduct: function (product, callback)
 
 
 ### Support
diff --git a/modules/billing.js b/modules/billing.js
index 1f1bda8..947834d 100644
--- a/modules/billing.js
+++ b/modules/billing.js
@@ -289,4 +289,31 @@ Billing.prototype.updateInvoice = function (invoiceid, opts, callback) {
   utils.modem(createOptions, callback);
 };
 
-module.exports = Billing;
+/**
+ * Capture payment - http://docs.whmcs.com/API:Capture_Payment
+ * @param invoiceid String|Number
+ * @param [opts] Object
+ * @param [opts.cvv] String
+ * @param callback
+ */
+Billing.prototype.capturePayment = function (invoiceid, opts, callback) {
+  var options = {
+    action:'capturepayment',
+    invoiceid:invoiceid
+  };
+
+  if(typeof opts === 'function'){
+    callback = opts;
+  } else {
+    options = extend(options,opts);
+  }
+
+  var createOptions = {
+    client: this,
+    body: options
+  };
+  
+  utils.modem(createOptions, callback);
+};
+
+module.exports = Billing;
\ No newline at end of file
diff --git a/modules/products.js b/modules/products.js
index 10800ef..fd2f23b 100644
--- a/modules/products.js
+++ b/modules/products.js
@@ -109,4 +109,35 @@ Products.prototype.getOrders = function(method, id, offset, limit, callback) {
   utils.modem(createOptions, callback);
 };
 
+/**
+ * Calculate the cost for an upgrade or downgrade of a product/service, and create an order for it.
+ * @param attributes Object
+ * @param [product.clientid] String
+ * @param [product.serviceid] String
+ * @param [product.type] String either "product" or "configoptions"
+ * @param [product.newproductid ] String
+ * @param [product.newproductbillingcycle ] String Must be unique if creating a sub-account
+ * @param [product.configoptions[x]] Array
+ * @param [product.paymentmethod ] String
+ * @param [product.promocode ] String optional
+ * @param [product.calconly ] String  optional
+ * @param [product.ordernotes ] String  optional
+ * @param callback
+ */
+Products.prototype.upgradeProduct = function (product, callback) {
+ var options = {
+    action: 'upgradeproduct'
+  };
+
+  for(var i in product){
+    options[i] = product[i];
+  }
+
+  var createOptions = {
+    client: this,
+    body: options
+  };
+  utils.modem(createOptions, callback);
+};
+
 module.exports = Products;
diff --git a/test/billing.js b/test/billing.js
index 0e10b9e..0516b3f 100644
--- a/test/billing.js
+++ b/test/billing.js
@@ -75,5 +75,40 @@ describe('billing', function() {
     });
   });
 
+  it('should create an invoice, capture payment and cancel it', function(done) {
+    this.timeout(15000);
+     
+    var invoiceo = {
+      'paymentmethod': 'moneris',
+      'date': '20141230',
+      'duedate': '20181230',
+      'itemdescription1': 'test item',
+      'itemamount1': 1,
+      'itemtaxed1': true
+    };
+     
+    client.billing.createInvoice(2, invoiceo, function(err, invoice) {
+      expect(err).to.be.null;
+      
+      client.billing.capturePayment(invoice.invoiceid,{cvv:'123'}, function(err, billing) {
+        expect(err).to.be.null;
+        
+        expect(billing.result).to.equal('success');
+        
+        client.billing.updateInvoice(invoice.invoiceid, {'status': 'Cancelled'}, function(err, data) {
+          expect(err).to.be.null;
+          
+          client.billing.getInvoice(invoice.invoiceid, function(err, invoice) { 
+            expect(err).to.be.null;
+            
+            expect(invoice.status).to.equal('Cancelled');
+
+            done();
+          });
+        });
+      });
+    });
+  });
+
 
 });
diff --git a/test/products.js b/test/products.js
index 2b5f55c..5ff2804 100644
--- a/test/products.js
+++ b/test/products.js
@@ -25,4 +25,30 @@ describe('products', function() {
     });
   });
 
+  it('should upgrade products', function(done) {
+    this.timeout(15000);
+    var opts = {
+      clientid : '1',
+      serviceid : '1',
+      type : 'product',
+      newproductid : null,
+      newproductbillingcycle : 'monthly',
+      paymentmethod : 'moneris'
+    };
+
+    client.products.getProduct(1, function(err, customer) {
+      expect(err).to.be.null;
+      
+      opts.newproductid = customer.products.product[0].pid;
+      
+      client.products.upgradeProduct(opts, function(err, product_info) {
+        expect(product_info.result).to.equal('success');
+          
+        expect(err).to.be.null;
+    
+        done();
+      });
+    });
+  });
+
 });