-
I'm not sure, to be honest.
If you need to register a child an a UK citizen, you need to have records from 5 years before their birth, so in my case over 10 years. I luckily have all that.
But other people in work just sent 5 years of proof for the past 5 years, if you have to get your qualifying period backdated to 10 years, yeah you do.
There's a good forum on facebook for questions if your acquaintance has questions. https://www.facebook.com/groups/132887737155325/
Are there circumstances in which you need 10 years of records? A Belgian acquaintance mentioned it.