This study aims to investigate the main factors affecting a consumer's choice of mobile phone service provider contracts, and to determine which of these factors are important in a consumer's decision-making process. As this decision is particularly pertinent within the contractual behavior setting, there is a need to explore the main factors that shape mobile phone subscriber choices when entering into a mobile phone telecommunication service contract. To do so, a set of mobile interrelated contract dimensions and a set of mobile service provider interrelated dimensions were identified and tested. The convenience sampling technique was employed and 400 questionnaires were distributed to mobile phone subscribers in Jordan with a response rate of 78.5%. By using the regression analysis, result analysis revealed that the main factor affecting consumer choices was "contract features", with a relative importance of 41%. After a set of mobile phone contract hypotheses were identified and tested, it was found that contract price, with about 15% relative importance, was the main contract feature that affected consumer choices, followed by the size of data that were related to the number of minutes and/or number of messages offered within the mobile service contract package. In addition, "company factors", with about 18% relative importance, were found to affect consumer choice of service provider contracts. The principal issue affecting consumer choice decisions was "switching cost", which was the highest relative importance element of company interrelated factors and found to influence mobile subscriber contracts choice significantly. However, other company factors like signal strength and sales outlet availability had no significant impact on consumer choices and ranked less for consumer-choice priority. More attention is needed from scholars to study the effect of other possible mobile phone contract dimensions from customers' perspective.