Why does the council think I'm married 😭

Last march I turned 18, meaning IV been 18 years old for 11 months.
Starting from April to now, my parents have received 5 letters from the council about sorting marriage paperwork out, I can't remember the exact wording, i was living at home for the first two letters, but the other three were sent while Iv been living at university
(Spread out through the year)
We all ignore them at this point but I'm wondering if anyone else had this experience or knows why its happening? IV never even been in a long term relationship 😭

Unfortunately, you don't have one essential piece of information: what the letters actually say.

The vague comment that they're "about sorting marriage paperwork" and that you "can't remember the exact wording" doesn't help.

Tax benefits and an application for a marriage certificate is what I remember from when I was living there, also they were all addressed to 'mrs' (name) instead of 'miss' (name)

Aren't you dying to find out if the Council has made an admin error or if someone has stolen your identity for a fake marriage and fraudulent benefit application?

Last march I turned 18, meaning IV been 18 years old for 11 months.
Starting from April to now, my parents have received 5 letters from the council about sorting marriage paperwork out, I can't remember the exact wording, i was living at home for the first two letters, but the other three were sent while Iv been living at university
(Spread out through the year)
We all ignore them at this point but I'm wondering if anyone else had this experience or knows why its happening? IV never even been in a long term relationship 😭