Proof of address

Hi, I've just received my ILR on a spouse visa and filling the application for naturalisation.
As a proof of living in UK for the last three years will be enough 3 council tax , 2021-2022, 2022-2023 and 2023-2024? I can't find the guidance how many letters I need to show.

Proof of address is not required, it’s proof of residency.
As ILR holder your passport with stamps in/out is normally sufficient.
Letters not required.

Thank you. Does it mean that I need to scan all pages of my passport or they will do it during biometric appointment?

UKVCAS will not scan any documents unless you book a paid service (over-priced) - you can scan and upload yourself for free. UKVCAS are not Home Office caseworkers. The only scan is for ID purposes only.