Logging into two Zoho accounts

Logging into two Zoho accounts

As I will be working with two different companies with Zoho forms, I have opened a Creator account for each company. 

Since many of the issues I have will be with both sets of forms, I tried to log into both accounts but it appears that Zoho will not let me do so.  Is this correct - one can not be logged into two different accounts at the same time?  Is so, why? - jb