[header] How to choose the right phone card [title] Determine the rate of the card offered to your calling destination (typically shown as ¢/min)? [step] Confirm rates before you call and remember that some rates may fluctuate. Also, calls made to international cell phones are generally billed at a higher rate. [substeps] Do the rates vary depending on the hour of the day? Be sure that the rate you receive remains constant throughout the entire day. 
Unless otherwise stated, the advertised rate should be constant no matter what time of day. [title] Consider the minute billing or minute rounding schedule for the card.