At a software company, billing is never “just billing”. One customer goes from 50 to 80 licenses mid-year, another switches plans, a third pays based on usage, and the CFO wants to know the exact ARR on the 1st of the month. Behind every invoice is a living contract.
NetSuite is widely used by software and SaaS companies, precisely because it brings contracts, billing, revenue and accounting together in one system. But when it comes to choosing how to manage subscriptions, the same question always comes up: should you go with SuiteBilling, NetSuite’s native module, Zab (now ZoneBilling, from Zone & Co), or a custom build?
At SuiteVise, our teams have supported software companies on NetSuite for several years, and we have seen all three approaches succeed… and fail. Here is how to make the right choice, and the pitfalls to anticipate.
What a software company really expects from its ERP
Before talking about modules, you need to talk about the business. A software company has needs that few other industries combine:
- Varied pricing models: flat subscription, per user, tiered, usage-based, or a mix of all of these.
- Contracts that change all the time: added licenses, upgrades and downgrades, proration, renewals, cancellations.
- Demanding revenue recognition: licenses, maintenance, services and subscriptions are not recognized the same way. The IFRS 15 standard requires revenue to be properly split and spread over time.
- Reliable SaaS metrics: ARR, MRR, churn, expansion. These are the numbers that management, the board and investors watch.
- A strong link with the CRM: contracts are very often created in Salesforce or HubSpot, and must flow cleanly into NetSuite.
- An international dimension: several subsidiaries, several currencies, different tax rules.
The right billing tool is the one that covers these needs without forcing your teams to recalculate everything in Excel.
The three options on the table
SuiteBilling: NetSuite’s native module
SuiteBilling is the subscription and recurring billing module developed by NetSuite. Subscription plans, price books, usage-based billing, renewals and amendments are managed directly in it, together with Advanced Revenue Management.
Its strengths: it is part of the NetSuite core, evolves with every release and doesn’t depend on any third-party vendor. For predictable subscriptions with few contract changes, it does the job very well. NetSuite itself positions it for this kind of need.
Its limitations: it becomes more rigid as things get complicated. Usage data generally has to be prepared outside NetSuite before being imported. Bundled offers and heavily amended contracts require workarounds. Consolidated billing for a customer across several subsidiaries and integration with a CPQ are also points to watch, as is performance with very large usage volumes. We cover other pitfalls in our article on the 5 pitfalls of a SuiteBilling implementation.
Zab (ZoneBilling): the specialized SuiteApp
Zab, now ZoneBilling from Zone & Co, is a SuiteApp installed directly in NetSuite. It doesn’t add an external system to synchronize: it extends NetSuite.
Its strengths: it was designed for complex cases. Usage data transformation directly in NetSuite, contracts that change often, customer hierarchies, multi-subsidiary billing, integration with Salesforce and CPQ tools. It also relies on Advanced Revenue Management for IFRS 15.
Its limitations: an additional license that costs more than SuiteBilling, a dependency on a third-party vendor, and an implementation that requires a good command of NetSuite and financial processes. For simple billing, it can be overkill.
Custom development: the temptation to build it yourself
The third way: rely on NetSuite’s standard billing and build the rest with SuiteScript scripts, custom records and workflows.
Its strengths: an answer tailored exactly to your rules, with no additional license.
Its limitations: it is often the most expensive option over time. Every billing rule becomes code to maintain, test with every NetSuite release and document. The knowledge rests with a few people. And the day the pricing model changes, which happens often at a software company, it has to be rebuilt. We rarely recommend it as a foundation, but it has its place alongside SuiteBilling or Zab, for a truly specific need.
How to choose: the criteria that really make the difference
| Criterion | SuiteBilling | Zab (ZoneBilling) | Custom |
|---|---|---|---|
| Simple, stable subscriptions | Very well suited | Possible, but sometimes overkill | Avoid |
| High-volume usage billing | Possible with upstream data preparation | Very well suited | Risky and costly to maintain |
| Frequently amended contracts | Acceptable, with workarounds | Very well suited | Complex |
| Multi-subsidiary, multi-currency | Acceptable, with limits on consolidated billing | Very well suited | Complex |
| CRM / CPQ integration | Requires integration work | Connectors available | Entirely to be built |
| License cost | Lowest | Higher | None, but development and maintenance costs |
| Dependency | NetSuite only | NetSuite and Zone & Co | Your developers |
| Adaptability if the pricing model changes | Good within the standard | Very good | Poor |
In practice, we always ask these five questions:
- What is your pricing model today, and in three years? A software company planning to move to usage-based pricing doesn’t make the same choice as one with flat subscriptions.
- How many contract changes per month? Beyond a certain volume of amendments, flexibility becomes the priority.
- Where do contracts come from? If they are created in a CRM or a CPQ, the quality of the integration is decisive.
- How many subsidiaries and currencies? International billing quickly complicates things.
- Who will maintain the solution? A skilled in-house NetSuite team, a partner, or nobody?
One simple rule sums up our experience: choose the simplest solution that covers tomorrow’s needs, not just today’s.
Challenges to anticipate, whatever the option
Choosing the module is only the beginning. Here are the topics that make or break a billing project at a software company.
- Revenue recognition. Both SuiteBilling and Zab rely on Advanced Revenue Management. It is a powerful but technical module: allocation and amortization rules must be designed with finance and the auditors from the start. A mistake here costs you at every close.
- Migrating active subscriptions. This is often the most delicate part. Every active contract must arrive with its dates, prices, past amendments, what has already been invoiced and the revenue already recognized. A badly migrated subscription means a wrong invoice at the next cycle and an incorrect ARR.
- The usage data flow. For consumption-based billing, you need to define where the data comes from, who checks it and how it reaches NetSuite in time for billing.
- CRM integration. You need to decide which system is the source of truth for the contract, the price and amendments, and avoid double entry between sales and finance.
- SaaS metrics. NetSuite doesn’t calculate ARR, churn or expansion the same way your board does. These metrics must be defined precisely, then built into dashboards.
- Price changes. A software company changes its offers regularly. The solution must let you create new plans without breaking existing contracts.
- E-invoicing. In France, every company has had to be able to receive B2B invoices through an approved platform since September 1, 2026. Issuing them is already mandatory for large and mid-sized companies, and will be for SMEs on September 1, 2027. The subscription solution must produce compliant invoices and fit into this chain.
Our method for making the right choice
Rather than starting from a preference for a tool, we start from your contracts.
- Map your real billing cases. We take a dozen representative contracts: the simplest, the most complex, the one with three amendments, the usage-based one, the one spanning two subsidiaries.
- Project your model three years out. New offers, a move to usage-based pricing, international growth, acquisitions: today’s right choice must still hold tomorrow.
- Test each option against these cases. For each contract, we check whether SuiteBilling or Zab handles it out of the box, with a workaround, or not at all.
- Calculate the total cost over several years. Licenses, implementation, additional development and maintenance: the cheapest solution to buy isn’t always the cheapest to run.
- Validate on a prototype. Before launching the full project, we test the most difficult cases in a test environment, with your teams.
This approach takes a few weeks. Above all, it avoids discovering, six months after go-live, that the chosen tool can’t handle your most important contract.
Frequently asked questions
What is the difference between SuiteBilling and Zab?
SuiteBilling is NetSuite’s native subscription module, suited to predictable recurring billing. Zab, now ZoneBilling, is a Zone & Co SuiteApp installed in NetSuite, designed for more complex cases: high-volume usage, frequently amended contracts, multiple subsidiaries, CRM integration.
Is Zab software external to NetSuite?
No. It is a SuiteApp that runs inside NetSuite, with no synchronization with an external system. It does, however, require a separate license.
Does SuiteBilling handle usage-based billing?
Yes, but usage data generally has to be prepared before it is imported. For large volumes or complex calculation rules, more specialized solutions are often a better fit.
Should you build your own billing solution in NetSuite?
Rarely as a foundation. Custom development is expensive to maintain and ages badly when the pricing model changes. It remains useful alongside a standard module, for a very specific need.
How does NetSuite handle IFRS 15 for a software company?
Through Advanced Revenue Management, used with both SuiteBilling and Zab. Recognition rules must be designed with finance from the start of the project.
Can you move from SuiteBilling to Zab later?
Yes, it is possible, but it requires a real project, especially to migrate active subscriptions. Hence the importance of projecting your needs from the start.
In short: there is no right tool, only the right choice for your model
SuiteBilling is ideal for predictable subscriptions and a team that wants to stay close to standard NetSuite. Zab brings the flexibility needed by software companies whose contracts and pricing models change a lot. Custom development, for its part, should remain a targeted add-on, never a default foundation.
The real risk isn’t choosing one option or the other. It is choosing without testing your real contracts against the tool, and finding out after go-live.
Torn between SuiteBilling, Zab and a custom solution? SuiteVise offers a scoping workshop for software companies: we analyze your contracts and pricing model and help you make the most relevant choice. Let’s take 30 minutes to talk it through.