Chapter 13 and the Relief from Automatic Stay

They file a motion. If the court allows the motion, the stay is lifted. I suggest that you not ask completely theoretical questions, either here or when talking to your own lawyer. Few legal questions have meaning outside the context of a specific case.

The main reasons would be if, as the Chapter 13 case progressed, you didn't keep up with the current mortgage payments. If you don't already know it, a 13 is complex to both prepare and file and also to keep up with in the process. I strongly recommend that you consult with a qualified bankruptcy attorney in your area.

The only way a mortgage company can obtain relief from stay in any bankruptcy case is by filing a Motion with the Court seeking an order. Typically, this happens either because there is no adequate protection such as a lack of insurance, or because the Debtor fails to stay current with his or her post petition secured debt payment to the lien holder. As others have already stated, Chapter 13 is a complex proceeding and should not be undertaken pro se. If you are concerned that your automatic stay protection is in jeopardy, I strongly advise you to consult with a local bankruptcy attorney experienced in Chapter 13 representation.

The main reason they lift the stay is when you miss post-petition payments. If you keep up the payments, most of the time you are fine.