Proof of residence

Hi everyone,

My wife received her indefinite leave to remain (PR) status in Feb of 2014. She is yet to apply for a British citizenship ans is planning to do one in the coming weeks. I'm a British citizen and she has been in the country for over 6 years now. I was wondering, if she is required to submit a proof of residence covering the time from Feb 2014 to date. Could someone point me to the right direction ?

For clarity, does she hold ILR or PR?? They are issued under completely different rules. PR is for EU nationals and their family members. ILR is the UK Immigration route one.

If she holds ILR after a UK immigration visa, then her passports are usually sufficient to prove residency.

Thanks for your response, she holds an ILR and she has got one of them Biometric cards with her as well .
She has had it since Feb 2014.I have been a British citizen since 2013, and I don't know if this is true that she need to provide proof of residence for the last 3 years. Or is that some old rules that were in place ages ago and has changed since then.

Could you please guide me to some links, if that's the case.