Access to the repository or a copy of the website source code repository.
User guide / development guide / administration guide / API of the existing site.
If you transfer a copy of the website to Cetera
The better way is to provide us access to the current website, as described in the section "If there is a working site". We'll create it copy and deploy at the new server.
If this isn't possible, then you need to provide us:
MySQL database dump in sql-file, in utf-8 encoding, in a separate archive.
A copy of all website file system, without any exceptions, in a separate archive.
A copy of all available website documentation in a separate archive.
Cetera will deploy the site received from you on a test hosting, check its performance.
If the site will be transferred to the "live" hosting Cetera, then, after deploy and check, you'll need to change the DNS settings for the website's domains.