The BR will be listed on the Insolvency Register and in the London Gazette and all of the banks, credit agencies, etc. normally scan these pages on a daily basis.
I am not 100% sure but you are probably legally obliged to disclose any information the OR requests as well.
You will be sent a pack by the OR which will need to be filled in. You list all your creditors on the form and also do a SOA. If you put up your SOA on the board the people here will check you have not missed anything.
Also, it's not the OR who freezes your bank account, it's the bank. Once the details have been published in the London or Edinburgh Gazette the bank will then freeze the account.
Tomorrow is a mystery, yesterday is history, today is the present, a gift to make the most of.