Build in-house
- Full control over product and roadmap
- Shaped to your exact process
- The IP stays yours
- Months to build, test and secure
- A standing team to maintain it
- You own the software lifecycle
Build vs buy
Finance AI: build it, or buy it?
An honest comparison of three routes: build your own system, configure a general-purpose AI assistant, or run Nummera in your Azure. Including when building is the right call.
Why it matters
Building is easier than ever. Owning it is not.
AI coding tools make a first version quick. The value is decided after that: getting it into production, staffing it, and trusting what it produces.
2×
AI built with specialist partners reached production about twice as often as internal builds: 67% against 33%.
MIT NANDA, The GenAI Divide, 202555%
of CFOs name hiring and developing AI talent as their top challenge right now.
Gartner CFO survey, 202666%
of employees rely on AI output without checking its accuracy. 56% have made mistakes in their work because of it.
KPMG and University of Melbourne, 2025
Nummera takes the first two off your plate and builds its product around the third: every figure is checked against its source before anyone reads it.
The comparison
How the three routes score.
Higher is better. Ratings reflect the typical outcome for a mid-market finance team, not the theoretical best case.
Build in-houseYour team builds it
General-purpose AIAn assistant plus your files
NummeraVerifiable AI for finance
Time to first valueWeeks, or quartersQuartersDays, for single tasksWeeks
Finance depthClose, variance, reportingAs deep as you buildGenericBuilt for finance
VerificationFigures checked against sourceYou build the checksManual reviewEvery figure checked
Data integrationsERP, BI, SharePointYou build each oneFile uploadsConnected, plus curated sources
Runs in your cloudYour Azure, in the EUWherever you chooseVendor’s cloudYour Azure tenant
AuditabilityFrom raw data to board packIf you build itLimitedFull trail
Keeping pace with AIAs models changeYour team’s jobVendor-drivenWe maintain it
Cost to ownTotal cost of ownershipHighLow, per seatSubscription
ControlShaped to your processFullPrompts and settingsConfigurable
Specialist talentLess is betterML, data and finance teamLittleNone extra
Best whenAI is your core product, and you have the team to own it.Quick, low-stakes drafting where mistakes are cheap.You want verified finance outcomes now, in your own Azure.
The pattern is consistent. Building wins on control. Buying wins on time to value. Nummera narrows the control gap by running in your own Azure.
Illustrative ratings. Weigh them against your own scope, team and requirements.
At a glance
The trade-offs, plainly.
General-purpose AI
- Instant to start
- Useful for ad hoc drafting and summaries
- No finance context or verification by default
- Output checked line by line
- Data processing on the vendor’s terms
Nummera
- Verified, explainable output for finance
- Runs in your Azure, in the EU
- Maintained as the models move
- Your needs must fit the platform
- You subscribe rather than own the software
The honest answer
When to build, and when to buy.
Build if
- A bespoke AI system is central to your strategy.
- You have a standing ML and data team with capacity.
- Your requirements call for deep custom development.
- You can fund the build and the years of upkeep.
Buy if
- You want better finance decisions this year, not a software project.
- Verification has to be built into the process.
- It must run in your own Azure, inside the EU.
- Your team should spend its time on analysis and judgment.
Buy the outcome. Keep the control.
Nummera runs in your Azure, on your data, with every figure verified. Start with one process and compare it with your own.