that help file link has nothing to do with Sage 100.  Here is the link to the Sage 100 Help Files (v2021); you can find help for your version by opening help from inside the installation or use this link.  https://help-sage100.na.sage.com/2021/index.htm#cshid=430001&chm=LM 

Sage includes the Visual Integrator Module for data import and data exports.  You will have to build according to your file layout and your module setups an import for AR_Customer, AR_Contact, and probably SO_ShipToAddresses.  Your reseller of record is really the best resource to assist you with implementing a new Sage 100 Application for your business. 

I agree with StefanouM..  Visual Integrator will do the heavy lifting.  Your reseller can save you lots of time by doing the first couple for you.  After that, you can try to do some or you may just decide to let the reseller design them for you.

Hi Gordon Storga, 

Thanks for reaching out. Noticed that the link you shared is for a different product for small business called Sage Accounting, the steps wouldn't apply to Sage 100. 

I was able to find your account ending 400xxxxx79 and see your Customer Portal / Sage Knowledgebase login of [email protected]

Most article help content for Sage 100 is gated so you'll need to login to the Sage Knowledgebase site in the top right corner in order to successfully search.

On the topic of importing / exporting data, you may want to review this article which points to the Getting Started Guide. In it you'll also find the mention that" if the Visual Integrator module is owned, some data can be imported into specific tables from source files - such as comma-separated variable (CSV) format - via user-created Visual Integrator jobs. Assistance from a qualified channel partner or consultant may be necessary, as Sage 100 Customer Support does not assist with creating import jobs. For more information," see this article.

Hope this helps!

Warm Regards, 
Erzsi

A very COMMON problem.  Due to Sage's marketing strategy, EVERYONE thinks they run "SAGE" only to find out while looking for information that they actually have Sage 50 or Sage 100 or Sage 100 Contractor or Sage 300 or Sage 500 or some other version of SAGE.  It is way too confusing!!  BTW, why isn't there a SAGE Intacct????  It is just Intacct!!!  And let's not even go down the "Cloud" road.

If you want to import these yourself - think about heading to Sage University and joining a course. The materials are typically very good and with a few hours of study, you may be able to learn what you need. Through March 31, 2023, there is a 50% off promo. 

sageu.csod.com/.../Welcome.aspx

Bringing your Sage Partner / Reseller into your project team will save you a lot of headaches.  Setup of a new Sage 100 system is not really a DIY / learn-as-you-go type activity... especially if you are talking about the more complex modules like job cost / manufacturing.