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It is perfectly fine for a corporation to have multiple accounts. Our adwords advisor has said this on several occasions. As long as you do not violate the double serving policy, its all fine.
In additon if you have multiple businesses in which you have controlling interest, and try to double server this way, you will also be violating the double serving policy.
I'm not sure what the policy is for individuals, but I assume it would be the same for a corporation.
But the driving factor behind the number of accounts, is not the number of accounts itself but the double serving policy.
The policy should read:
For each Business (or multiple business's in which you have controling interest) - One account per unique product brand.