Splitting founder equity

What are best practices on splitting founder equity? Does that change if a co-founder joins after incorporation? 

Back in April of last year, I took the plunge and incorporated my venture, deciding to kickstart things and leave the co-founder search for later. Now, with a fully launched B2C product (my second attempt after the first one didn't quite make it), I've realized the importance of having a co-founder, especially in the eyes of potential investors. I've identified a few potential candidates, but I'm unsure about the logistical aspects of equity splitting.

Is it necessary to go through a reincorporation process to adjust share distribution? Do I need legal assistance for this, and if so, would it be more cost-effective to undergo reincorporation, considering I already have established company bank accounts and other operational elements in place?

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Yuan Onida
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