Can my dog still get his papers registered after he's a year old?

Hi my name is Elizabeth and I have a German Shepherd named Skippy he's a year and one month my question is someone told me I can't get my dog's papers registered after a dog is a year old or older I looked online but couldn't find anything I would like to know if it's true cuz I would love to get my dog's papers register now that I have the money for it I hope it's not too late he is a fun loving dog and would love to see a litter of cute squirmy puppies made by him I hope someone can help thanks. 🐕🐾