Someone asked me to find this out for them and any advice would be very much appreciate. Just don't press me for too much on particulars, I'm posting as much as I know! 
Let's pretend the business owner is called Charlie Murphy and he is a printer.
This is the sequence of events:
*Charlie sets up business as a sole trader 25 years ago, and calls himself 'Charlie Murphy Printing'
*Charlie opens a business bank account in his local bank, in his own name (account name just reads 'Charlie Murphy', not 'Charlie Murphy Printing')
*It never occurs to Charlie to register the business name, as he isn't setting up a company
*Charlie registers the business for VAT, gets a VAT number, and all is fine with the Revenue, they never ask for a certificate of registered business name
*Business trades happily for 25 years, Revenue are happy with the accounts etc, all is well
*Charlie uses the business name on invoices and customers make out cheques to 'Charlie Murphy Printing', and the bank accepts these for payment into the business account
*Now, 25 years later, the bank is refusing to honour any cheques made out to Charlie Murphy Printing until they see a certificate that the business name has been registered
Registering the business name is not a problem and Charlie is perfectly happy to do this. The form asks how long has he been using the business name and since he's had a VAT number for 25 years he'll be putting down '25 years'. Will it cause any difficulty with the Revenue that the business name wasn't registered until now?
Let's pretend the business owner is called Charlie Murphy and he is a printer.
This is the sequence of events:
*Charlie sets up business as a sole trader 25 years ago, and calls himself 'Charlie Murphy Printing'
*Charlie opens a business bank account in his local bank, in his own name (account name just reads 'Charlie Murphy', not 'Charlie Murphy Printing')
*It never occurs to Charlie to register the business name, as he isn't setting up a company
*Charlie registers the business for VAT, gets a VAT number, and all is fine with the Revenue, they never ask for a certificate of registered business name
*Business trades happily for 25 years, Revenue are happy with the accounts etc, all is well
*Charlie uses the business name on invoices and customers make out cheques to 'Charlie Murphy Printing', and the bank accepts these for payment into the business account
*Now, 25 years later, the bank is refusing to honour any cheques made out to Charlie Murphy Printing until they see a certificate that the business name has been registered
Registering the business name is not a problem and Charlie is perfectly happy to do this. The form asks how long has he been using the business name and since he's had a VAT number for 25 years he'll be putting down '25 years'. Will it cause any difficulty with the Revenue that the business name wasn't registered until now?