Unable to enter zip code with leading zero

[Jesse36682746ewk8]

I am just trying to fill in my zip code in a PDF form and my zip starts with zero but it won't allow it. If I change the first digit it accepts. There are thousands of zip codes with zero in front what gives? How do I get this to work? 

[Thom Parker]

Did you create this PDF? 

The problem is almost certainly related to the field formatting. 

[JR Boulay]

You should use the Zip code format.