With interest rates at their highest levels in two decades, subnational governments (SNGs) are grappling with growing debt sustainability concerns. This paper investigates SNGs’ financing vulnerabilities by examining their debt levels and sensitivity to interest rate fluctuations. It provides an in-depth analysis of SNG debt portfolios, with a particular focus on marketable debt or bonds. While most SNG bonds have fixed rates and long maturities, some jurisdictions are significantly exposed to interest rate and foreign currency risks. Simulations reveal that interest expenses could rise substantially for some SNGs. Yet, worryingly, the variation in borrowing costs among SNGs within countries is often limited, suggesting potential weaknesses in market discipline. To navigate these challenges, the paper briefly explores how well-crafted fiscal rules, tax autonomy, and insolvency frameworks can help mitigate risks. It also highlights the need for further assessment of bank loans, as systematic information remains scarce. The paper provides insights for policymakers seeking to address risks and inform future reforms of SNG bond markets, reinforcing market discipline and bolstering fiscal resilience.