Ensuring that fieldworkers use airtime for its intended purpose can be a challenge. It’s notoriously difficult to track and control airtime usage for prepaid SIMs.

One way to prevent airtime being used for personal calls and messaging is to convert it into data – which can only be used for internet connectivity from the handset. Although it is still possible for a fieldworker to use data inappropriately (such as for personal web browsing), the risk of large amounts of airtime being used is significantly reduced.

On the Vodacom network for example, there are a number of ways to purchase prepaid data bundles, but a really simple way to purchase a data bundle is via SMS. Once you’ve provided the fieldworker with sufficient airtime, they must simply be instructed to send an SMS specifying the bundle they need to purchase to a toll-free number. For example, to purchase a 5MB data bundle from Vodacom, they would send “MYMEG 5″ to the Vodacom short code “100″.

Purchasing a 5MB data bundle from Vodacom via SMS

To simplify the process even further, it may be worthwhile to save this message as an SMS template (supported by most handsets), which the fieldworker can use to initiate the request when instructed by a supervisor (usually on a monthly basis).

At the time of this post, a 5MB data bundle from Vodacom cost R9.25 and data bundles can carry over for a maximum of 60 days. More information on pricing and data bundle options can be found on Vodacom’s website.

You can also use USSD to purchase data bundles. MTN offer a similar service, via USSD, whereby the fieldworker dials a “USSD string” depending on the size of the bundle they wish to purchase. More info is available on MTN’s USSD FAQs page.

Even a 5MB data purchase is usually sufficient for even the most productive fieldworker – although obviously this depends on the nature and frequency of the data they collect.