I’ve found myself with little need for a cell phone now that I’m working from home — I just use it for occasional solo errand runs and as security against freak roadside emergencies. So I’ve switched to Boost Mobile’s “pay as you go” plan.

The plan is designed for this situation. There’s no monthly fee or contract; I just bought the phone outright (paying all of $30 for a basic “makes calls, sends texts” phone) and I pay 10¢ a minute any time I make or take a call.

Here’s what’s not in their marketing: credit on your account expires in just 90 days. The actual policy reads:

Note: You must add money to your account at least once every 90 days.If not, any unused credits in your Boost™ Prepaid Account Balance will expire and your account will go to zero, but don’t worry because your account will be automatically recharged with Auto Re-Boost.

“Don’t worry” — it’s okay that we’ll throw away your money if you haven’t paid us in a while, ’cause then we’ll immediately come take more money automatically! Since the smallest automated payment they’ll take is $15, that’s a guaranteed minimum expense of $5 / month, even if the phone was turned off the entire time.

That’s called a monthly fee. Let’s not kid ourselves.

Yes, I could turn off “Auto Re-Boost” (their automatic payment plan), but that doesn’t stop credit from expiring; it only stops it getting replenished automatically. I’d still have to pay them every three months, but with the added risk that I might forget and render my phone unusable. On the other hand, manual payments can go as low as $10, making the monthly cost a lower $3.33.

I’ve had the phone for three weeks now, and in that time I’ve rung up $1.90 in calls, with 90¢ of that on initial setup (e.g., validating Google Voice and trying to disable voicemail).

(For the record, the “pay as you go” plan does not support conditional call forwarding, but you can disable voicemail entirely. You just have to call Boost until you get someone who knows what you’re talking about.)

It’s a lot better than $50 / month, but we’ve got a long way to go before this is quite the service it’s made out to be.