Unlimited vs per-minute AI phone plans: how to choose

Work out your minutes before you look at a single price

Most people choose an AI phone plan backwards. They compare prices, then guess at how much they'll use. Do it the other way round, because the right plan depends almost entirely on two things: how many minutes you use in a month, and how much that figure jumps around.

The short answer, if you're in a hurry. Few calls and unpredictable ones? Pay per minute. Steady use, month after month? A plan with minutes included is simpler and usually kinder to your budget. And if a plan says unlimited, read the fair-use terms before you believe the word.

Do the sum on the back of an envelope

You need three numbers: calls per working day, average length, and working days in the month. Your phone already has the first two. Open the call log, scroll back four weeks, and look at how long the calls ran.

Say Graham runs a two-van plumbing outfit. He misses about five calls a day while he's under a sink, and an intake call runs about two minutes. Over 22 working days that's 220 minutes answered. He also hands off a dozen outbound calls a month, to suppliers and customers, at three minutes each. Call it 36 more. His figure is around 256 minutes.

Then nudge it upwards, for two reasons. Many plans round each call up to the next whole minute (ours does), so forty seconds counts as one. And hold time counts. If your assistant waits 25 minutes in an airline queue, that's 25 minutes connected.

Read what unlimited means in the terms

An unlimited plan is a flat price with a promise that you won't count minutes. That's a real comfort if counting makes you anxious. But somebody is paying for every minute of those calls, so nearly every unlimited plan carries a fair-use policy. It's the most important page on the site and the one fewest people open.

We're not going to tell you what any particular company's policy says, because we can't vouch for it and it may have changed. Here's what to look for in whichever one you're reading:

• A figure in minutes or calls, somewhere in the terms, above which use stops being "fair".
• A cap on the length of a single call, which matters if you want hold queues handled.
• What happens when you go over: slower service, a forced move to a pricier plan, or a bill.
• Whether outbound calls are included, or only answering.
• Whether unlimited applies per line or per account.

Pay per minute if your use is low and spiky

A per-minute plan has no allowance. You use ten minutes, you pay for ten. For low and spiky use that's hard to beat: a seasonal business that's silent from November to March, a side project, a line you're testing before you commit. You're not paying for a quiet month.

Two cautions. First, check what the minute includes. On some developer platforms the per-minute figure is one line among several, with the phone number, the voice and the telephony each charged separately, and the true cost is the sum. Second, per-minute platforms are often built for people who write code. If you're comfortable assembling the parts yourself, fine. If you're a florist, you may spend more in evenings than you save in dollars.

There's a psychological cost too. When every minute is on a meter, people start rationing calls they should be making.

Take an allowance if your use is steady

An allowance plan is the middle road: a monthly price that includes a block of minutes, and a per-minute rate if you run past it. If your use is steady, this is usually the easiest to live with. You know the bill in advance, and a busy week doesn't produce a surprise.

The weakness is the mirror image of per-minute. In a dead month you've paid for minutes you didn't use. In a frantic one you'll pay extra. So pick the allowance that fits an ordinary month, not your best one, and ask three questions before you sign: how are extra minutes charged, is each call rounded up, and do texts or emails eat into the allowance?

Check our plans against your number

Ours are allowance plans. Each one includes the phone number, the line's email address, the connection to your assistant, and a block of call minutes. Go past the block and extra minutes are charged individually. A minute is time connected on a call, in or out, rounded up per call. Texts and email never use minutes.

So the allowance is a figure you can read on the plan, and you can hold it against the one from your envelope. Plans start from $29 a month, and the allowances and the rate for extra minutes are on the pricing page. Plans may change, so that page is the one to trust. If you want the wider picture of what drives the bill, there's what a phone number for an AI agent costs.

Look elsewhere if either of these is you

If your envelope sum came out at a handful of calls a year, a monthly plan of any kind is poor value. A per-minute platform will cost you less, provided you're happy to build on it.

If it came out in the thousands of minutes, with many calls running at once, you're describing a call center. That's a different kind of product with a different kind of contract, and we've written about the gap in what small businesses need is not what enterprises buy.

Common questions

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