All businesses should prepare standardised documents for their correspondence and invoices. An invoice is basically a standard letterhead with the addition of a number of billing points. The examples set out here assume that your business is a limited company.
If you are a sole trader or if you operate as a partnership, you can ignore the bits about a company registered number and registered office address.
Your trading address must be included in all cases. If your company registered office and your principal place of business are one and the same, that you only need to show the address once, provided that it is clear that they are one and the same!
You can only use a VAT invoice if you are VAT registered. The Excel file has an example of a non-VAT invoice on tab 1 and an example of a VAT invoice on tab 2. Please use the correct one.
There are strict rules about invoicing by VAT registered businesses. They are set out in detail at:
Reg 14(1)(i) The Value Added Tax Regulations 1995
The letterhead legislation is set out here and it includes a requirement that you show these details on your web site and somewhere within your emails:
The Companies (Trading Disclosures) Regulations 2008
and
The Companies (Trading Disclosures) (Amendment) Regulations 2009