No, there are no licensing requirements for Forensic Document Examiners in the majority of jurisdictions in the United States or Canada, or in most other parts of the world. Some sort of licensing would have tremendous benefit by providing a degree of regulatory oversight. However, like other forensic disciplines, there is nothing at present for Forensic Document Examination work.
Therefore, please do not assume that anyone offering their services is truly qualified and competent. Check their credentials carefully. To that end, look closely at any professional certification held by the examiner. Certification speaks to the competencies and capabilities of the examiner. In addition, review the examiner’s curriculum vitae (resume) carefully and always ask questions about anything in it.