Four structures cover almost every vendor in this category, and the structure changes your total far more than the sticker rate does.
Per user per month
This is the most common model and the easiest to forecast, because the bill is headcount multiplied by a fixed rate. When I Work, Deputy, Sling, ZoomShift, and Buddy Punch all work this way [1][2][6][8][7]. Check who the vendor counts as a user first, since ZoomShift bills any manager, team member, or employee occupying an active spot [8], so back-office staff who never take a shift still land on the invoice.
Per location per month
Homebase and 7shifts charge a flat rate per site with no per-employee component at all [3][5], so a 40-person restaurant and a 12-person coffee bar pay the same $56 or $79.99 for the same tier. That makes average headcount per site the number worth modeling, not total headcount.
Base rate plus overage
Connecteam charges a flat rate for the first 30 users in each hub and then a per-user rate above that, varying by hub and tier: $0.80 on Operations Basic annually, $2.50 on Advanced, and $4.20 on Expert [4]. Buddy Punch adds a $19 monthly base fee to every per-user plan [7]. Price the tier at your real headcount, because the overage rate is where a 200-person deployment separates from a 30-person one.
Quote only
Enterprise vendors publish no rate card. Legion routes every pricing conversation to a demo request and sells labor planning, schedule optimization, time and attendance, and employee engagement as separate modules [10]. Workday does the same, with contact-sales as the only path to a number [11]. Deputy moves to a quoted Enterprise plan above its published tiers [2]. Ask for the per-employee rate, the minimum committed headcount, and the term in writing.
Annual billing discounts
Annual prepayment cuts the rate by a published percentage: 18% at Connecteam [4], up to 18% at Buddy Punch [7], 15% at Sling [6], and 10% at 7shifts [5]. Homebase quantifies it per plan instead, at $72, $168, and $288 saved per year [3]. The trade is cash timing against rate, and it rarely pays off if your headcount swings seasonally.