As far as I know, if the mortgage is overdue for half a year without receiving the notice, there may be the following reasons:

First of all, banks usually stipulate penalties for overdue repayment in mortgage contracts, including penalty interest and late fees. If the overdue time is short, the bank may remind the borrower to repay the loan as soon as possible by phone or SMS. However, if the overdue period is long, the bank may need to take more severe measures, such as claiming compensation from the guarantor or initiating legal proceedings. In this process, the bank will make necessary investigations and preparations, which may take some time.

Secondly, before communicating with the borrower, the bank will often get in touch with the borrower's emergency contact to determine the borrower's whereabouts and understand the situation. If the borrower fails to provide accurate contact information within the overdue period or the contact information has expired, the bank may not be able to get in touch with the borrower in time, resulting in failure to notify the borrower in time.

Finally, the bank's process of handling overdue cases will also have an impact on the timeliness of notification. Generally speaking, the bank will first conduct internal audit to confirm the borrower's overdue situation and possible breach of contract, and then the professional team will be responsible for collecting the borrower or taking other corresponding measures. This process may take some time to ensure the legitimacy and accuracy of the program.

To sum up, the failure to receive the notice that the mortgage is overdue for half a year may be due to the bank's need for necessary investigation and preparation, inaccurate or expired contact information, and internal procedures for handling overdue cases. If your mortgage is overdue for half a year and you haven't received the notice, I suggest you contact the bank as soon as possible to understand the relevant situation and take the initiative to solve the problem.

Extended data:

Overdue repayment may lead to the damage of the borrower's credit record, which will further affect the individual's credit score and future loan application. Therefore, overdue repayment is a situation that needs to be avoided as much as possible. If you can't repay the loan on time, please communicate with the relevant banks or financial institutions and seek solutions. Banks usually provide short-term busy loans, deferred repayment and other measures to help borrowers tide over the difficulties.