extension entrepreneur HMRC welcome letter issue

[tang8866]

hi everyone, here is my question
I was under PSW VISA in 2008-2010 and i have been registered as self-employee on that time(the welcome letter was issued on dec.2008). In May 2010 I got my first three year entrepreneur VISA now i am making the extension but i can't get welcome letter any more as i already registered as self-employee. in immigration guidance says that 'You must provide evidence of your registration within the 6 months after your specified date. Your specified date can be the date of entry to the UK (if you were given Entry Clearance and have the evidence of your date of entry), or the date of your grant of entry clearance, or the date of your grant of leave to remain if you applied in the UK.' So, do i still required this welcome letter?