ISO/ITIL for startup

Answer:
Organization can't be ITIL accredited, only ISO 20000. If you, as an organization, would like to show excellence in IT Service Management (ITSM) - ISO 20000 is the right way to do it.
However, if you don't need (ISO) certificate - just implementing ITIL (usually, only part of it) is also right way to go.
Startup - sure, why not. But, resource wise, you will need certain amount of people (employees) to be involved. Namely, e.g. for ISO 20000 implementation, you need to implement various processes and usually, some of the process managers can't be (or, it's not advisable to ) combined.

Read the following articles to get more information:
"What ITIL roles can be combined in one person?" https://advisera.com/20000academy/knowledgebase/itil-roles-can-combined-one-person/
"What’s needed for successful ISO 20000 certification of your company?" https://advisera.com/20000academy/blog/2016/05/24/whats-needed-successful-iso-20000-certification-company/
"ITIL Certification" https://advisera.com/20000academy/knowledgebase/itil-certification/

Hi,

Thank you for your Quick answer.

How would I go about achieving ISO 20000 accreditation for a Startup I.T Business

Assuming you have defined the scope (since you are startup, most probably - whole organization, but read the article "How to define the scope of the SMS in ISO 20000" https://advisera.com/20000academy/blog/2015/06/02/how-to-define-the-scope-of-the-sms-in-iso-20000/ to help yourself) and certification body, you can use this free implementation diagram to guide you through implementation:
"ISO 20000 implementation diagram" https://info.advisera.com/20000academy/free-download/iso-20000-implementation-diagram

This article will help you with documentation structure "How to structure ISO 20000 documentation" https://advisera.com/20000academy/blog/2016/09/27/how-to-structure-iso20000-documentation/
This free material will provide you with different implementation options:
Comparison matrices for ITIL / ISO 20000 implementation solutions https://advisera.com/20000academy/comparison/
and, if you decide to do it by yourself, you can use "ISO 20000 Documentation Toolkit" https://advisera.com/20000academy/iso-20000-documentation-toolkit/ to speed up the implementation.