What proof of funds do estate agents usually need at initial offer stage?

[ScaredSceptic]

We viewed a house yesterday and will be making an offer tmw morning. My husband is going overseas this evening for work for a week. So I'm trying to make sure I have whatever I might need from him to give to the estate agent (we have savings in various accounts, some in my name, some in my husband's).

I'm not talking about the anti money laundering checks, but just the initial proving to the estate agent that we have the funds to back up the offer.

I'd be grateful if you could tell me what you had to provide and in what format to get offer accepted - paper statements? PDF statements? Screenshots of statements? Did you also have to provide ID immediately? Did you have to go to the office with original ID documents, or were copies/screenshots of ID sufficient?

I'm just trying to get an idea of what is usual so I can hopefully make sure I have everything I need, as it's just unfortunate timing with my husband about to go away.

When we where buying they wanted proof principle mortgage offer from the bank. They normally give you a certificate to prove it. Unless you are a cash buyer.

I had to show my bank statement of my savings account with my full name and address on it.
Eta ID check was online and I needed my passport and had to take a photo of my face.

I had an online ID check that required my passport and a face scan (my husband was away with work and did this remotely) and needed to give my mortgage offer decision in principle. This was just a DIP done online from the website of the mortgage broker company we used.

That's really useful, thank you all.