Next you must cancel all joint credit cards. Also call and remove your spouse as an additional cardholder on any of your own credit cards. This action will of course alert your spouse that you are leaving, so it is best to do it immediately before leaving, or just before filing for divorce.
Are these extreme measures? Not if you have already decided to file for divorce. If your spouse decides on a split before you do, you may find yourself presented with a situation where all or most of these things have already been done. You may also find that the arrangements aren’t as fair as they should be. If you think your divorce will be amicable, answer this: Have you and your spouse talked about it quietly? Have you each hired an attorney, and selected a neutral mediator to help with the details? If this is not the case, and you have made your decision, and one person’s departure from the home is imminent, then you should take these actions now.