Birth Registration

My daughter was registered twice, 2 years apart. We had her before we were married, but told at the first registration, we could return after marriage and register her again, so she wouldn't be classed as illegitimate. We did this 2 years later, when we registered our second child.

I'm into family history and have found many errors in the records of ancestors, so probably not uncommon.

My husband discovered years ago when the bum bailiff turned up, that he and another baby boy born 3 minutes apart at the main hospital in Copenhagen had been registered and baptised with the same first and second Christian name and had the same surname. Their fathers had the same Christian names as well, and were not the same person. Being born only a few minutes apart they had consecutive social security numbers with only one digit's difference between the two numbers.

So he could prove he hadn't defaulted on payments, as the social security number on the citation was not his.

Perhaps OP's finding was caused by something similar.