I no longer live in Singapore; however, I occasionally use some services (mostly banking) that require a Singaporean number for text message verification. What's the cheapest way I can retain a Singaporean number valid for this?
For the time being I've kept my regular Singtel SIM, but even the cheapest postpaid plan is >$20/month. I'dI'd prefer to avoid prepaid numbers, because I'm leery about them running out of credit/validity and not being able to renew while overseas, but I'm open to suggestions.