With the rise of cheap small cells in wireless cellular networks, there are new opportunities for third party providers to service local regions via sharing arrangements with traditional operators. In fact, such arrangements may be particularly desirable for large facilities—such as stadiums, universities, and mines—as they already need to cover property costs, and often have fiber backhaul and efficient power infrastructure. In this paper, we propose a network‐sharing arrangement between large facilities and traditional operators. Our network‐sharing arrangement consists of two aspects: leasing of data access and spectrum from traditional operators; and service agreements with users. As a consequence of the incorporation of the user service agreements into the sharing arrangement, financial as well as physical resource constraints need to be accounted for. This introduces a new dimension into wireless network resource allocation, which requires a new evaluation framework. To this end, we develop a framework based on ruin theory, where the key metric is the probability that the facility is insolvent within a fixed time period. We then investigate the effect of initial capital and physical layer parameters on the ruin probability, which provides insight into the robustness of the network‐sharing arrangement to varying conditions.