Determining the best ISO 13485 consultancy company can depend on various factors including your specific needs, location, budget, and the reputation of the consultancy. Here are a few well-regarded ISO consultancy company as follows:

BSI Group: BSI offers a range of services including ISO 13485 certification and consultancy. They have a global presence and are known for their expertise in quality management systems.

SGS: SGS is another global leader in inspection, verification, testing, and certification services. They offer ISO 13485 certification and consultancy services as well.

TÜV SÜD: TÜV SÜD is a trusted name in certification and testing services. They provide ISO 13485 certification and consultancy to medical device manufacturers worldwide.

MSCincorporation: MSCincorporation is a recognized ISO 13485 consulting firm offering a wide range of services, including ISO 13485 certification consultancy. MSCi has extensive experience in auditing and certification across various industries.

NSF International: NSF International offers a variety of services including ISO 13485 certification and consultancy. They have a strong focus on the healthcare and life sciences industries.

LRQA (Lloyd's Register Quality Assurance): LRQA provides ISO 13485 certification and consultancy services to help organizations achieve compliance and improve their quality management systems.

When selecting a consultancy company for ISO 13485, it's essential to research each option thoroughly, and consider their experience in your industry, customer reviews, certifications, and any additional services they may offer. Additionally, reaching out to each consultancy for a consultation or quote can help you determine which one best fits your needs and requirements.