Uganda's digital credit market is dominated by two mobile network operators — MTN Uganda (MoMo Loans) and Airtel Uganda (Okoa) — whose overlapping yet structurally differentiated loan portfolios collectively serve more than 1.3 million active borrowers. This mixed-methods study examined the composition, uptake determinants, and default risk profiles of digital loan portfolios offered by these two providers, using data collected from 1,240 active borrowers across five districts in the Greater Kampala Metropolitan Area and a purposive sub-sample of 60 in-depth interview respondents. Univariate analyses revealed that borrowers were predominantly male (57.0%), aged between 26 and 35 years (33.8%), and earned monthly incomes in the range of 200,000 to 499,999 UGX (38.9%). MTN borrowers maintained significantly higher mean loan values (87,400 UGX vs. 74,800 UGX, p < 0.001) and longer repaymentperiods compared to Airtel borrowers, while Airtel borrowers recorded higher mean interest rates (14.1% vs. 12.3%, p < 0.001). Bivariate analysis identified statistically significant differences in agricultural loan uptake (χ² = 5.28, p = 0.038), repeat borrowing prevalence (OR = 1.28, 95% CI: 1.01–1.62, p = 0.048), and mean loan values. Multilevel logistic regression modelling, accounting for district-level clustering (ICC = 0.143), revealed that low income (Q1 AOR = 4.39, p < 0.001), loan stacking (AOR = 2.32, p < 0.001), and provider type — Airtel versus MTN (AOR = 1.36, p = 0.026) — were independent predictors of default. Qualitative analysis identified five dominant themes: accessibility, trust and reliability, financial burden, regulatory awareness, and provider preference, which contextualised and explained the quantitative findings. The study concluded that the two providers serve differentiated but overlapping borrower segments, and that systemic regulatory reform, improved borrower financial literacy, and product redesign are urgently needed to mitigate growing household debt burdens in Uganda's digital credit ecosystem.