What is the difference in treatment of intercompany transaction(trading) with regards to sole company & that of group company accounts?

Trading with sister companies (intercompanies) are subject to consolidation adjustments in Sales, COGS, AR, AP and Inventory in Group's (combined or consolidated accounts) for fair presentation of Group's financials.

While in individual accounts of each company is subject to disclose related party transactions separately in notes to the accounts.

Intercompany transactions arise when there is trading between two intercompanies  that are owned by one owner, like in sales,AR,AP, COGS, Inventory.  the treatment is: adjustments will be made to these accounts before consolidation

For Sole company when the owner has only one company, there is no intercompany transaction , so no consolidation need to be made 

With regards to sole company, there is no intercompany accounts as there is only one company. Intercompany or related party transactions will only arise where  there are two or more companies by the same owners.