First AI Employee vs. IsOn24: flat price vs. a per-minute meter

What does a busy month actually cost when the meter counts faster than the clock on the wall? IsOn24 and First AI Employee both answer your phone around the clock, both book appointments, and both send texts. The difference is who does the work and how the bill is calculated. IsOn24 is a self-serve product that has been around since 2014, and it meters your usage by the minute. First AI Employee is done for you and charges one flat price with included minutes, so the number on your invoice holds steady from month to month, and no meter starts unless you switch one on.

The short version

If you want a predictable bill and someone else to build and run the receptionist, First AI Employee is the better fit, and here's the case in plain numbers. IsOn24 bills per minute with monthly minute caps, starting at $59 a month for 1,000 minutes, and its texts are capped on the same plan, so a busy month presses two meters at once. The detail that quietly does the damage is the toll-free multiplier: every actual minute on a toll-free number counts as 2.5 against your cap, so a ten-minute call draws twenty-five. The meter runs faster than the clock. To be fair, IsOn24 is an established product that bundles two-way texting and booking rather than charging extra for them, and we'll grant that. But First AI Employee starts at $99 a month for 300 minutes with no multiplier and no meter running unless you opt into overage, the build is handled for you, and the published price is the price. Every metered month you stay, the toll-free calls you can't control are spinning a meter you can't see until the invoice lands.

What the meter leaves out

A per-minute plan looks simple until the call volume moves. On IsOn24 the published tiers are Starter at $59 for 1,000 minutes, Sprinter at $99 for 3,000 minutes, Sprinter Plus at $149 for 4,500 minutes, and Cruiser at $199 for 7,500 minutes, with Enterprise priced on request. You can read the full table on the IsOn24 plans page. Every one of those tiers is a cap. Cross it and you are into overage or a forced upgrade, and the texts are capped on the same plan as well, so a busy month pressures two meters at once.

The detail that is easy to miss sits in the fine print. Toll-free inbound minutes are counted as 2.5 minutes for every real minute of conversation. A ten minute call on a toll-free line draws twenty-five minutes from your allowance. The meter runs faster than the clock. There is a second drain too: the IsOn24 plans page says outbound minutes, the ones used while forwarding an incoming call to another number, also count toward your usage, so a call that gets answered and then transferred pulls from the same allowance twice. First AI Employee does not meter at all inside your plan, so a long call is just a long call, transferred or not.

What self-serve leaves out

IsOn24 is something you set up and tune yourself. The product is capable, but the configuration and the ongoing care are on you. The hands-on help is tiered: every plan includes onboarding and email support, but as of June 2026 the plans page says live phone support starts at the $99 Sprinter tier, so the entry $59 Starter plan is email-only. A dedicated specialist who helps tune the agent for your trade only comes with the $199 Cruiser tier, roughly four times the entry price. On a lower plan, when something needs adjusting, you are largely on your own.

There is also some fine print worth reading before you commit. As of June 2026, IsOn24's own cancellation and refund policy states it 'offers no refunds, even if you cancel a plan mid-month,' and that annual subscribers get no refund or credit for unused months either. Subscriptions also 'renew automatically at the end of each term,' and you have to give 'at least seven days' written notice before the term ends to stop the next one. Miss that window on an annual plan and you are renewed for another prepaid year with nothing refundable. First AI Employee bills month-to-month with no lock-in and nothing to time.

First AI Employee works the other way. The agent is built and run for you, tuned to how your business actually talks to customers, and it is answering your calls in minutes. You never open a builder. Optimization and support come with the service at every tier, not just the expensive one. After each call you get a summary and a transcript, and booked appointments land on your calendar. See how it works.

One honest point in their favor

IsOn24 is an established product, and unlike some rivals it does bundle two-way texting and booking rather than charging extra for them. That is a real strength. The catch is that those texts are capped too, and the price is still tied to a meter that runs faster on toll-free numbers.

If you would rather skip the builder and the math, First AI Employee gives you a flat price, bundled SMS on Basic and Standard, no setup fee, and a receptionist that someone else keeps in tune. You don't have to settle it on a plans page. Put it on your own line for seven days, free, and hear it answer before a meter ever enters the picture. Start the free trial and decide with your own ears.