Typically, after a divorce is finalized, one spouse cannot be held responsible for mortgage debt incurred by the other spouse unless there are specific circumstances or agreements in place that dictate otherwise. Once the divorce is finalized, each spouse's financial responsibilities and liabilities are generally determined and legally separated. However, exceptions may exist, such as if both spouses remain co-owners of the property and agree to share mortgage responsibilities post-divorce. It's essential for individuals to understand their rights and obligations regarding mortgage debt in their specific situation and to consult with legal experts if needed.

In Nigeria, the court can hold one spouse responsible for mortgage debt incurred after the divorce is finalized if:

1. The debt was incurred jointly: If both spouses signed the mortgage agreement together, they will both be liable for the debt, even if the divorce has been finalized.

2. The debt was used to benefit the marital home: If the mortgage debt was used to renovate or improve the marital home, the court may consider it a marital debt, and both spouses may be held responsible.

3. There is a court order: If the court order granting the divorce includes provisions for the payment of the mortgage debt, the spouse responsible for the payment may be held in contempt if they fail to meet their obligations.

4. The debt was incurred before the divorce was finalized: If the mortgage debt was incurred before the divorce was finalized, both spouses may still be liable for the debt, even if the divorce has been finalized.

However, if the mortgage debt was incurred solely by one spouse after the divorce was finalized, without the other spouse's knowledge or consent, the other spouse may not be held responsible.

It's essential to consult with a lawyer to understand the specific circumstances and the applicable laws in Nigeria.