Order Long Form Birth Certificate
A birth certificate copy is still an official document, printed on official paper, and can be identified as a proper document. A photocopy is not necessarily accepted by any or all government entities, and in most cases will be refused. In today's world, it's increasingly hard to do anything that is government run without your identification papers.
Your birth certificate has specific information about you. It shows where you were born, when you were born, your nationality, weight at birth, and even the time of your birth. It shows your legal name at birth, and in many cases, the names of your mother and father, and helps show lineage. Many birth records also have another identification number, not your national insurance number assigned to them.