do you have the original bonds.
If not maybe when they computerised manual records they kep't he process simple by using set dates or maybe they misskeyed it?
If there originals was there a relative maybe dad with same name or could there of been a older barry who died as a baby?
I think Bobbinwales has it. When old style records are transferred to modern computer systems, often general dates are used rather than accurate specific ones.
I am the only Barry in the family. I do have an older sister that died when she was 2 but that was years before premium bonds were released.
I do have the original bonds.
I will phone them up
Puzzle solved. The bonds I have are not the originals as I thought but duplicates. When they digitised old bonds they didn't know when the original bonds were issued so used a placeholder date - 1st January 1957.
I have been assured that the bonds are mine and were sold after I was born.