The financial turnover in the oil and gas industry is significant, making the reliability of measurements in custody transfers essential. Compliance between producers and consumers needs to be strict to avoid commercial disputes. This work aims to use the guard band methodology to define acceptance limits in transfers of crude oil, anhydrous ethanol fuel (AEF), diesel S-500 and liquefied petroleum gas (LPG), to reduce the risk of wrong decisions when assessing compliance. The methodology is based on the application of measurement uncertainty with guard bands to define acceptance limits, thus guaranteeing a 95 percent confidence interval. This method reduces the risk of accepting a non-conforming item, which is detrimental to the consumer, and the risk of rejecting a conforming item, which affects the producer. Thus, the acceptance intervals established were: crude oil from -1.0824 to 0.6879; AEF from -0.6286 to 0.3324; diesel S-500 from -0.6423 to 0.5632; and LPG from -0.4355 to 0.0893, based on the percentage differences between producer and consumer measurements. It should be noted that this approach can be more conservative and restrictive compared to current methods, providing greater confidence in oil and gas industry transactions. Consequently, both producers and consumers benefit from a significant reduction in the risks of incorrect compliance assessments.