diff --git a/accounting.js b/accounting.js
index 755a3d5..d313655 100644
--- a/accounting.js
+++ b/accounting.js
@@ -176,7 +176,9 @@
 	 *
 	 * Doesn't throw any errors (`NaN`s become 0) but this may change in future
 	 */
-	var unformat = lib.unformat = lib.parse = function(value, decimal) {
+	var unformat = lib.unformat = lib.parse = function(value, decimal, failure_result) {
+		if (failure_result === undefined)
+			failure_result = 0;
 		// Recursively unformat arrays:
 		if (isArray(value)) {
 			return map(value, function(val) {
@@ -203,7 +205,7 @@
 			);
 
 		// This will fail silently which may cause trouble, let's wait and see:
-		return !isNaN(unformatted) ? unformatted : 0;
+		return !isNaN(unformatted) ? unformatted : failure_result;
 	};
 
 
diff --git a/index.html b/index.html
index 2f3b3f4..2df0b14 100644
--- a/index.html
+++ b/index.html
@@ -297,14 +297,20 @@ <h4><strong>accounting.toFixed()</strong></h4>
 		<h4><strong>accounting.unformat()</strong></h4>
 
 		<pre class="prettyprint lang-js">// Standard usage and parameters (returns number):
-accounting.unformat(string<em>, [decimal]</em>);
+accounting.unformat(string<em>, [decimal], [failure_result]</em>);
 
 // Example usage:
 accounting.unformat("GBP &pound; 12,345,678.90"); // 12345678.9
 
 // If a non-standard decimal separator was used (eg. a comma) unformat() will need it in order to work out
 // which part of the number is a decimal/float:
-accounting.unformat("&euro; 1.000.000,00", ","); // 1000000</pre>
+accounting.unformat("&euro; 1.000.000,00", ","); // 1000000
+
+// if passed string is not a number convertible, unformat fails and return 0
+// you can specify failure_result response of your choice for flexibility and avoid ambiguity.
+accounting.unformat("&euro; Not a Number", ","); // 0
+accounting.unformat("&euro; Not a Number", ",", "failed"); // "failed"
+</pre>
 
 	</section>
 
diff --git a/tests/qunit/methods.js b/tests/qunit/methods.js
index 19e354b..0e679e9 100644
--- a/tests/qunit/methods.js
+++ b/tests/qunit/methods.js
@@ -7,6 +7,8 @@ $(document).ready(function() {
 		equals(accounting.unformat(1234567890), 1234567890, 'Returns same value when passed an integer');
 		equals(accounting.unformat("string"), 0, 'Returns 0 for a string with no numbers');
 		equals(accounting.unformat({joss:1}), 0, 'Returns 0 for object');
+		equals(accounting.unformat("string", ',', null), null, 'Returns user specified failure response for a string with no numbers');
+		equals(accounting.unformat("string", ',', "failed"), "failed", 'Returns user specified failure response for a string with no numbers');
 
 		accounting.settings.number.decimal = ',';
 		equals(accounting.unformat("100,00"), 100, 'Uses decimal separator from settings');