*If I arrive in the UK on 25th October(assuming no-deal Brexit happens on 31st October) and I rent a flat, open a bank account and have a phone contract from Vodafone or some other carrier, is that enough proof for my arrival or do I need to live certain amount of months to qualify for pre-settled status?
I am an EEA national. Imagine I go tomorrow to France,
rent a flat, get a landline, a broadband, open a bank account in a local branch...
Does it show I was in France during that time? Yes. There is a paper trail to demonstrate it.
Does it prove I was exercising Treaty Rights and actively trying to settle in France?
No.
Renting a flat or opening a bank account doesn't fund the Treaty Rights. I was in Ireland the other day and I have a receipt for groceries and fuel. These are private transactions similar to renting a flat, and don't mean anything by themselves.
Read this document, it shows how to the UK Government tests if someone is exercising Treaty Right:
https://assets.publishing.service.gov.u ... Policy.pdf
The document itself is about children born in the UK to EEA nationals. They explain how to tell if the EEA national is exercising Treaty Rights (As opposed to an EEA national who just happened to visit the country).
As an EEA national, it's not because you happen to be in the UK at one point that you can demonstrate you were effectively exercising Treaty Rights.
This category is close to what you want I think:
It means, if you arrive October 25th, 2019, it won't be about renting a flat or getting a SIM from Vodafone, but actively looking for a job and being able to demonstrate it later.
When you are working, it's easy because you get payslips that demonstrate salary and contributions. But if you are not working, you need to distinguish yourself from the tourist visiting London to take photos.
If we crash with no deal, the relationship with the EU can get nasty and you don't want the Home Office to tell you later you weren't exercising Treaty Rights before October 3st, so you have no right to be in the UK under pre-Brexit EEA regulations.
You can also read this:
https://www.gov.uk/government/publicati ... ter-brexit
There will be still provisions for EEA nationals arriving after October 31st but they won't be classic EEA routes as we know them. They are talking about some schemes but the details are not fully known yet.