Project name and address
Dear [Name] 
Following your acceptance to the invitation to tender for the above we are pleased to enclose the following:
Technical information as set out on the accompanying drawing issue sheet [to include all plans, sections, elevations, details, diagrams, specifications, schedules and so on; send 2 copies if posted]
The form of tender [send 2 copies if posted] 
Copies of the relevant advance orders [if applicable]
The completed form of tender is to be returned to the above address/emailed to [add email address]* by [date].
Please acknowledge receipt of this email/letter* and enclosed information and confirm that you are able to submit a tender in accordance with these instructions.
Yours faithfully,
[Name]
For and on behalf of [Company name]

* Delete as applicable