SaaS licensing explained: seats, usage, enterprise agreements and contract terms

A renewal quote for one of your SaaS tools lands next month. It lists more seats than people who log in, a line for “overage” nobody remembers agreeing to, and a price increase. Finance wants to know what you are actually licensed for before anyone signs. You need to read the license the way the vendor wrote it.

A SaaS license is the contract right to use software that the vendor hosts: who may use it, how much, for how long and at what price. Unlike old installed software, you never own a copy. You rent access, and the license metric decides what you pay for. For the basics of the model, see What is SaaS?.

A SaaS license in plain terms

Think of parking at an office. One company buys a named permit for each employee’s car, whether the car comes in or not. Another pays the meter for the hours it actually parks. A large company leases the whole lot for three years at a negotiated rate. The parking spaces are the same. What changes is what gets counted, and who pays for the empty spaces.

SaaS licensing works the same way. The vendor picks a license metric, the unit it counts and bills. The contract then adds the term (how long you commit), the renewal rules and what happens when your count goes up or down.

The four common license metrics

The table compares the four metrics you will meet most often. Each example comes from the vendor’s own public page, as of October 2026.

Metric	What is counted	Who pays for unused capacity	Public example
Named user (seat)	Each person given access, active or not	You	GitHub lists Team and Enterprise plans per user per month (GitHub pricing)
Active user	Only people who used the product in the period	The vendor	Slack credits members inactive for over 28 days (Slack fair billing policy)
Usage	Units of work: tasks, API calls, events, volume	Nobody, but cost is harder to predict	Zapier counts “tasks” per month (Zapier pricing); Stripe Billing charges 0.7% of billing volume (Stripe Billing pricing)
Enterprise agreement	A negotiated bundle: seat bands, usage pools, term, price protection	Depends on the bands you commit to	Usually “contact sales”; terms are private

Named seats are simple. They are easy to budget and easy to over-buy. Active-user billing moves the risk of idle seats to the vendor. Usage metrics fit products whose value grows with volume, but your bill moves with your business. For how each metric shapes the vendor’s price list, see SaaS pricing models.

How active-user billing works

Slack’s fair billing policy is a public, precise example. A member counts as inactive when they have not used Slack “in over 28 days”. The workspace then receives a credit for the unused part of the billing period. Slack’s own formula is the cost per member divided by the days in the month, times the days left. Its help page works it through as ($8.75 / 30 days) x 15 days = $4.38. If the member comes back, Slack charges the prorated cost for the rest of the period.

Not every vendor works this way. Under a named-seat license, an employee who left in March still costs you a full seat until someone removes them, and sometimes until the next renewal.

Contract terms that change the bill

The metric sets the unit. These terms decide how much of it you pay for:

• Term and renewal. Annual and multi-year terms usually come with a discount and an automatic renewal. Note the notice period: miss it and you renew at the vendor’s terms.
• True-up. A clause that bills you for seats added during the term, often at a review date or at renewal.
• Seat reduction rights. Many contracts let you add seats at any time but reduce only at renewal. Some do not let you reduce at all within a multi-year term.
• Price increase cap. A limit on how much the per-unit price can rise at renewal. Without one, the renewal price is whatever the vendor quotes.
• Feature gating. Some features sit only in higher tiers. GitHub’s plan cards list SAML single sign-on on Enterprise and not on Team. A security requirement can force the whole company onto a higher tier.
• Caps by plan. Some plan families have a seat ceiling. The Microsoft 365 Business plans stop at 300 users, as worked through in Microsoft 365 as SaaS.

Worked example: an annual seat license with a true-up

Example: a labeled hypothetical. You license 200 named seats at $12 per user per month on a 12-month contract, paid annually.

• Annual license cost: 200 x $12 x 12 = $28,800.
• A login report in month 6 shows 160 active users. Idle seats: 200 - 160 = 40.
• Cost of idle seats for the year: 40 x $12 x 12 = $5,760, or $5,760 / $28,800 = 20% of the contract.
• In month 7 a new team joins and you add 30 seats. The true-up clause bills them for the remaining 6 months: 30 x $12 x 6 = $2,160.
• Total for the year: $28,800 + $2,160 = $30,960.

Now look at what happened. You paid $2,160 for 30 new people while 40 paid seats sat unused. If the contract had allowed reassigning idle seats, the new team would have cost nothing extra. Reassigning 30 of the 40 idle seats to the new team would have saved the full $2,160, and the 10 left over show what to cut at renewal.

The same 40 idle users under active-user billing like Slack’s would have earned credits instead. At $12 per member and a 30-day month, Slack’s formula gives ($12 / 30) x 30 = $12.00 per idle member per full month, or 40 x $12.00 = $480 a month.

Checklist before you sign or renew

• Find the license metric in the order form, not on the pricing page. They can differ.
• Pull a login report for the last 90 days and count active users against licensed seats.
• Remove or reassign seats of people who left before the true-up date.
• Read the seat reduction clause: can you go down at renewal, or never within the term?
• Find the renewal notice period and put it in a calendar 30 days earlier.
• Ask for a price increase cap in writing.
• List the features your security team requires, such as single sign-on, and check which tier includes them.
• For usage metrics, take your last three months of usage and price the busiest month, not the average.

For how the same per-seat logic plays out in a CRM purchase, see CRM SaaS.

Common mistakes

1. Paying for seats of people who left. Named seats cost the same whether anyone uses them. Why it happens: offboarding removes email access but not every SaaS account. Instead: tie seat removal to the offboarding checklist and run a login report each quarter.
2. Buying a seat for everyone who might need access. Every read-only viewer costs a full seat on many plans. Why it happens: it is easier than handling access requests. Instead: check for viewer, guest or lower-cost seats, and share reports by export where you can.
3. Missing the renewal notice period. Auto-renewal at the vendor’s new price is the default. Why it happens: the notice date sits in the contract, not in anyone’s calendar. Instead: record the date when you sign, with a reminder 30 days before it.
4. Budgeting usage licenses at the average month. Usage bills follow your busiest periods, and overage rates are often higher than the included rate. Why it happens: averages look tidy in a spreadsheet. Instead: price the peak month and ask for the overage rate in writing.

Sources

• Slack, Fair billing policy, checked October 2026.
• GitHub, Pricing, checked October 2026.
• Zapier, Pricing, checked October 2026.
• Stripe, Billing pricing, checked October 2026.

In three sentences

A SaaS license sets a metric (named seats, active users, usage or a negotiated enterprise bundle) plus the term, renewal and change rules that decide what you pay. In the example, 40 idle seats out of 200 waste $5,760 a year, and a $2,160 true-up for 30 new users could have been avoided by reassigning them. Read the metric in the order form, count active users before every renewal and get seat reduction, notice period and price cap terms in writing.