This study aimed to (1) examine the borrowing and repayment behavior related to informal debts among small-scale retail entrepreneurs in the Nakhon Si Thammarat Municipality; (2) investigate whether demographic characteristics are associated with differences in borrowing and repayment behavior; and (3) analyze the economic factors influencing such behavior. This research employed a quantitative methodology, using a structured questionnaire as the primary data collection instrument. The sample consisted of 400 small-scale retail entrepreneurs operating within the municipal area of Nakhon Si Thammarat Province. The collected data were screened for completeness and accuracy and subsequently analyzed using frequency distributions, percentages, and the Chi-square (χ²) test to examine the research hypotheses. The findings revealed that the borrowing and repayment behavior of respondents demonstrated a continued reliance on informal lending sources, largely due to inadequate financial support from the government. Most entrepreneurs reported borrowing amounts ranging from 30,001 to 40,000 THB, typically every two months, with repayment periods extending beyond three months. The prevailing interest rates ranged between 15% and 20% annually, while many borrowers indicated a willingness to accept rates above 8%. Monthly installment payments were the most common method, with most participants consistently meeting their obligations in a timely manner, covering both principal and interest. Furthermore, significant differences in borrowing and repayment behavior were observed based on demographic characteristics, including gender, age, education level, marital status, household size, personal financial responsibilities, and the types of products sold (p < 0.05). In addition, key economic variables—namely daily income and daily business expenditure—also had a statistically significant influence on debt-related behavior (p < 0.05).