Under EU Commission Directive 2002/4/EC all egg production sites must be registered. Since January 1st 2004 and all eggs must carry a code for identification purposes.

The new codes will tighten up on the Free Range Market where often cage produced eggs were sold as Free Range. All eggs can be traced back to their production site.

All eggs, wherever they are sold, must be marked. Do not buy unmarked eggs as their origin could be doubtful.

Below is a chart explaining the new codes.
 

First Digit 0 Organic Eggs or 1 Free Range Eggs or 2 Barn Eggs or 3 Eggs From Caged Hens Two Letters UK Country Of Origin Last Five Digits e.g. 99999 Farm ID Example 3UK11992 Broadland Eggs

Eggs are sold by weight and below is a chart detailing the weight ranges for all sizes.