The Financial Post reports in its Tuesday edition that the country's telcos are overhauling their data systems to prepare for new accounting rules. The Post's Emily Jackson writes that only a handful of reporting periods remain for the companies to comply with new revenue reporting rules under international accounting rules, which could drastically change important industry performance indicators such as average revenue per user when implemented by Jan. 1, 2018. The standard chiefly affects wireless contracts that couple smart phones with voice, data and text plans. Instead of spreading out the revenue from the smart phone -- customers typically pay for a phone over two years, resulting in higher monthly revenue -- the telcos will have to recognize the revenue upfront. The amount of money changing hands remains the same, but it could look like companies are getting less each month. Considering there were 28.8 million wireless subscribers in Canada in 2015, all with diverse plans that consumers can change on a whim, it will take a lot of heavy lifting to recalculate each contract. "The mass amount of data is what I would argue would be the biggest challenge," Telus chief financial officer Doug French told the Post.