DBD Ltd sales since the commencement of trading on 1 July 2011 have been as follows:

The above figures are stated exclusive of VAT.
The company's sales are all standard rated and are made to VAT registered businesses.
DBD Ltd only sells goods and since registering for VAT has been issuing sales invoices to customers that show:
(1) The invoice date
(2) DBD Ltd's name and address
(3) The VAT-exclusive amount for each supply (4) The total VAT exclusive amount
(5) The amount of VAT payable of VAT payable
The company does not offer any discount for prompt payment.

Required:
(i) Explain from what date DBD Ltd was required to compulsorily register for VAT and state what action the company then had to take as regards notifying HM Revenue & Customs (HMRC) of the registration.
(ii) Explain the circumstances in which DBD Ltd would have been allowed to recover input VAT incurred on goods purchased and services incurred prior to the date of VAT registration.
(iii) Explain why it may be beneficial for a company to voluntarily register for VAT.
(iv) State the additional information that DBD Ltd must show on its sales invoices in order for them to be valid for VAT purposes.