Being a co-signer for a home loan does not affect your credit score. Unlike a co-applicant for a joint home loan, a co-signer is not responsible for making regular payments on the loan. However, if the borrower defaults on EMI payments, your credit score will take a hit.
Additionally, if the debt goes unpaid, it will reflect in your credit report and this will hamper your ability to increase your score. Remember, maintaining a good score helps prove your creditworthiness to lenders and allows you to secure cost-effective home loan interest rate offers.