At the moment I am using the IP address/subfolder (12.34.56.78/folder for example) to contain the site files. When it comes to switching the 3rd party domain name to point to the new hosting provider, is it as simple as just changing the site URL’s in the general settings on the WordPress dashboard?

Yes, you’d want to modify the General Settings to reflect the actual URL of the website. Personally, I like to do this through PHPMyAdmin modifying the Options table.

I’m assuming that the /folder lives right below the public_html folder (i.e. /home/user/public_html/folder). If that’s the case, I’d recommend moving these files up a level to be inside the public_html folder.

If you’re using a FTP program, you could select all the files in the sub folder, and drop them in the appropriate directory.

If you’re using SSH, you can simply run:

mv folder/* .

Also will I need to add a CNAME or an A name with the 3rd party domain provider as I am pointing to a ‘/subfolder’. At the moment if I just type in the Web address without the ‘/folder’ bit, I get a blank white page.

Apache actually controls all of this for you. That’s why I recommend moving the files inside the public_html directory (or the directory configured in Apache for your public-facing files).

Once the files are in the right place, you should be all set to point the domain to the IP address, given the proper DNS entries are in place.

domain.com IN A 12.34.56.78

If you didn’t build/configure the hosting environment, you may want to get with the web host, or the person that did first, to make sure you’re moving things to the proper directories :).

Good luck!