Making the transition from 2005 to 2013 revision of ISO 27001

Answer: I assume your company is already certified against 2005 revision of ISO 27001, and now you want to certify against 2013 revision - yes, this needs to be done with a certification body.

See also:
- article How to make a transition from ISO 27001 2005 revision to 2013 revision https://advisera.com/27001academy/knowledgebase/how-to-make-a-transition-from-iso-27001-2005-revision-to-2013-revision/
- webinar recording: What’s new in ISO 27001 2013 revision: How to make the transition from ISO 27001 2005 to 2013 revision https://advisera.com/27001academy/webinar/transition-iso-27001-2013-to-iso-27001-2022-free-webinar-on-demand/

What is the process of the reassessment with the assessing body, do they look at all the internal audit work during the assessment ?

Answer: Until now your 2005 certificate has expired because the transiti on period is over, so you have to go for the completely new certification against 2013 revision of ISO 27001. And yes, they will look at how you're done your internal audit, and they will check also all the other elements of your ISMS.

See also:
- article Which questions will the ISO 27001 certification auditor ask? https://advisera.com/27001academy/blog/2015/07/20/which-questions-will-the-iso-27001-certification-auditor-ask/
- article Becoming ISO 27001 certified – How to prepare for certification audit https://advisera.com/27001academy/iso-27001-certification/

If during the assessment there were some areas that needed addressing, then does the company get an opportunity to put a plan together to rectify and still maintain the certificate ?

Answer: Yes, if the certification body finds nonconformities, they will give you a deadline until which you'll have to resolve those problems.

See also:
- article Major vs. minor nonconformities in the certification audit https://advisera.com/27001academy/blog/2014/06/02/major-vs-minor-nonconformities-in-the-certification-audit/