Services
These days, translators don't work with pen and paper. Instead, they use cloud-based CAT tools designed to automate the translation process. This explains the reason why digital formats work best for source documents.
Translation tools are designed to work with various formats, including read-only ones. However, they cannot process handwritten texts, which have to be retyped and converted into an electronic document.
If the document consists entirely of handwritten text, you might need a sight translation service.