Postal Code Required for Account/Checkout

I'm not sure if this was mentioned yet, if so I apologize, I wasn't able to find it, but it would be nice if you could set the Postal Code in Account Creation and/ or Checkout to Require the Postal Code.

I was playing around creating customers and noticed that I didn't input a Postal/Zip Code.
This is probably not as important as the rest of the requests, but something I thought would be necessary as this cart grows.

The reason for this is, if the customer does not input a postal code then we have to get in touch with every customer who didn't provide one in order to ship the product.

I'm not sure if anyone has run into this yet, but I could see it becoming a big problem for sites that generate a lot of sales.
I know most people will probably input their Postal Code out of habit, but it seems it would be better if they can't proceed without putting in their Postal Code.

Thanks Daniel for all the hard work on a great shopping cart.

I asked this very question and it was pointed out that Ireland don't use a postcode etc...

If you only plan to sell to the uk then you can mod the code to make it a required field.

Yeah. I modified the code, but the the next update will probably wipe out my changes and I'll have to make those changes again.

Maybe it could be an option in the admin?

Post your changes as it may help others with add or making required fields in OpenCart.

I am not familiar with how one would mod the code to get this. Where do I go to do this and what do I put in to Mod the code? Thanks