If you make an agreement with your business partner that you will ALWAYS reach agreement on ANY business item that comes up, no matter how strongly you both feel and no matter how far apart on an issue, your partnership will thrive.
If you are in a business partnership, call your bank and find out if you have a joint account. If you are “on” the account but it’s not a joint account, change it.
Is it legal for your partner to lock you out of your business? Maybe. But, even if legally possible, they had better have a very good reason or things could go very wrong for them.