Knowledgebase
How to make the state or province field required or not in Magento
During the checkout process the state/province field at the address step can be required or not depending on the country selected by the customer. Of course, for some countries this is essential so that tax and shipping can be properly configured and calculated. In such cases the state/province field is required. For some countries such as Canada and the United States Magento is preconfigured to require the customer to specify the state.
You can make the state/province field required for other countries, and you can also make it a non-required field for those for which it's set to be required. To do this, log in to the admin panel of your Magento and go to System menu>Configuration>General button in the General section on the left>State Options panel on the right. The State Options panel contains a couple of options. The first one is State is required for and it consists of a long list of countries. By default, some of these countries are marked which means that the state/province field for those countries is required. To mark/unmark countries in this list press and hold the Ctrl button on your keyboard and click on the country names with the left mouse button.
Under the list with the countries there's a drop-down menu Display not required State which is set to Yes by default. This means that for those countries for which the state/province field is not required it will be displayed on the frontend but customers will not be required to specify a value in that field. If you want this field to be hidden for countries for which it's not required, just set the drop-down menu to No.
If you make any changes, don't forget to click on the Save Config button.