This scientific article comprehensively examines financing policies and their impact on the sustainability of micro, small, and medium-sized enterprises (MSMEs) in the textile sector in the municipality of Maicao, Colombia. The study addresses the issue from a multidimensional perspective, considering the inherent volatility of border markets and the barriers to formal credit that these organizations face. Its main objective is to evaluate how working capital management and investment strategies influence long-term viability and the transition to sustainable business models. A mixed methodological approach was used, with a non-experimental, cross-sectional, and descriptive-explanatory design. The sample consisted of ten representative companies from the sector, analyzed during the period 2023–2024. The results reveal that 60% of companies adopt conservative financing policies based on self-financing, which limits growth but protects immediate liquidity. A critical finding is the hyper-concentration of assets in inventory (from 55% to 68%), which increases the risk of obsolescence in a fast-fashion environment, specifically in slow-moving inventory and accounts receivable, thus increasing vulnerability to demand shocks and obsolescence risks. The discussion expands to include integrated sustainability, analyzing environmental and governance dimensions. The study concludes that the financial sustainability of the sector in border areas depends not only on capital injections but also on a structural transformation that prioritizes financial literacy, the digitization of accounting processes, and diversification toward formal financing sources and risk management tools. Strategic guidelines are proposed to improve financial inclusion and regional competitiveness in a globalized and highly dynamic market.