New front end web design job, old developer continue hosting?

I've recently taken on a front-end redesign job for a small business who have a WordPress site. Their previous web developer billed them for the original design and sends them annual invoices for the hosting and domain registration fees.

I will need ftp access to the site to change thing around as well as WordPress login details but is it reasonable for me to ask the previous web developer to continue to host the site on their server to avoid me having to set up new hosting and change everything over or are there some issues that might come up in this situation?