Hi,
Maybe John was born with a different surname then his mother married a William BARRETT. This one could be possible,
Birth
John A FRENCH Dec Q 1918 Poplar 1c 557
Mother's Maiden Surname: French
Marriage
William BARRETT Sep Q 1923 Poplar 1c 771
Rose FRENCH with same details.
He might never have known that his birth name was FRENCH.
Long time in replying, however with the 1921 Census release, I have just found my grandfather John Alfred Barrett living in Silvertown (a stone's throw from his birthplace of Poplar) aged 2 years 8 months (see attached). This confirms Oct 1918 was his correct birthdate all along, which re-ignites the mystery of no matching birth record.
Interestingly, his mother is listed as Rose, which aligns with the theory posted above! The only snag is, Rose is apparently already married to William in the 1921 Census, whereas the marriage record posted above was for 1923.
Did people lie about their marital status back then? If they weren't married, wouldn't it have been illegal for Rose and John to have used William's surname?
If my Grandfather was indeed born John Albert French, is there a way to find out if his surname was legally changed to Barrett? Was it even a legal requirement in those days?