A plain-English guide to building any billing term: flat fees, usage-based, tiered pricing, one-offs, and recurring.

How Tabs is structured

Everything flows top-down.

A customer can have multiple contracts, each contract can have multiple products (billing terms), and each product generates invoices on a schedule you define.

Customer
  ↓
Contract
(one deal / agreement)
  ↓
Product (billing term)
(one chargeable line item)
  ↓
Invoice
  ↓
Invoice line items

What is a product?

A product (also called a billing term or obligation) is a single chargeable item on a contract — like one row on a sales order.

A contract can contain multiple products.

Example

Each product is configured independently and generates invoice line items automatically.

The five building blocks

Every product is made up of five core decisions.

1 — Product details

Basic commercial configuration.

Includes

• Product name

• Quantity

• Currency

• Net terms

• Tax settings

• Description

Example

Platform Fee
Qty: 1
Net 30

2 — Revenue dates

Defines when the service is actually delivered.

This controls:

• Revenue recognition

• Service periods

• Proration behavior

Example

Jan 1 → Dec 31

3 — Cadence & duration

Defines how often invoices are generated.

Common cadences

• One-time

• Monthly

• Quarterly

• Annually

• Custom schedules

Example

Invoice monthly for 12 months

4 — Pricing model

Defines how the amount is calculated.

Common pricing models

Examples

Flat fee

$2,000/month

Unit pricing

25 seats × $40

Usage-based

$0.05 per API call

Tiered pricing

0–1,000 units → $0.10
1,001–10,000 → $0.08

5 — Invoice timing

Defines when invoices are generated relative to the service period.

Common timing options

Example

Invoice monthly in advance on the 1st

Putting it together

A full billing term combines all five decisions.

Example: SaaS subscription

Result

12 invoices generated automatically,
one on the 1st of each month.

Common billing patterns

One-time onboarding fee

• One-time cadence

• Flat fee pricing

• Immediate invoicing

$5,000 billed at signing

Annual prepaid subscription

• Annual cadence

• Flat fee pricing

• In advance invoicing

$24,000 billed upfront annually

Monthly seat-based SaaS

• Monthly cadence

• Unit pricing

• In advance invoicing

25 seats × $40/month

Usage-based API billing

• Monthly cadence

• Usage pricing

• In arrears invoicing

Bill monthly based on actual API usage

Tiered enterprise pricing

• Monthly cadence

• Tiered pricing

• In arrears invoicing

Different usage tiers billed at different rates

HubSpot users

Invoices and payments sync automatically once the product is configured.

Mental model

Contract = commercial agreement
Product = one billing obligation
Invoice = scheduled output of that obligation

Configure the product correctly, and Tabs automatically handles invoice generation.