You must give a written statement to every subcontractor you make a deduction from, each time you pay them for the CIS. You have to do this within 14 days of the end of each tax month.
You can easily access CIS Payment and Deduction Statements from the Reports section. They're also accessible by clicking 'more' in the sub menu when viewing a Subcontractor record.
You can save yourself a lot of time by automating the distribution of CIS Statements.
Go to the Subcontractosrs record in the Employee section and ensure you've entered an email address for them.
Once an email address has been entered you'll see a checkbox appear labelled 'Automatically email CIS Statement'
Whenever a CIS 300 is accepted by HMRC, we check to see if any of the Subcontractors included have this option enabled and automatically email them a PDF of their Payments and Deductions statement for the relevant month.
You can cusomise the content of the email by clicking the employer name in the main menu and going to Settings -> Templates.
If you want to see for yourself that the email has been sent then you can view your Mail Logs.