Enterprise finance teams pay for software that shortens the month-end close, reduces reconciliation workload, and makes audit preparation less painful. Stacks, a UK-based finance automation platform, is positioning itself squarely in that workflow and has raised a EUR 23 million Series A led by Lightspeed, with participation from General Catalyst, EQT Ventures and s16vc.
Stacks targets account reconciliations, journal entries and close management, with a product narrative that emphasises replacing manual stitching across ERP systems, spreadsheets, data warehouses and legacy applications. The company says it provides a data layer that consolidates finance data into consistent views, then automates repetitive work using a mix of AI agents and deterministic machine learning.
Why this round matters
This financing lands in a well-established and increasingly contested part of CFO software: close and reconciliation platforms. Incumbents such as BlackLine, HighRadius and OneStream are entrenched in many large organisations, but Stacks is explicitly arguing that those systems can be costly and poorly rated, creating an opening for a more implementation-friendly alternative.
The underlying pain is familiar to any controllership team: fragmented data leads to manual reconciliation, duplicated checks, and slow cycles that compound at month-end and during audits. Stacks is selling into that operational reality with a value proposition that is measured in hours and days saved, not abstract transformation language.
Traction and ROI signals
Over the past 12 months, Stacks says it onboarded 30 enterprise clients, including Pleo, Cleo, Motorway and Bloom & Wild. The company also cites quantified customer outcomes: a 47% reduction in book closing time, a 97% decrease in manual reconciliations, and 33% faster audit cycles, alongside 100,000 hours saved in reconciliation work.
Customer-level examples include Motorway reducing reconciliation time and Juni cutting its financial close by 3.5 days, which Stacks equates to roughly 40 hours per month for typical teams. The company also highlights its Flux reporting tool, which it says can reduce reporting cycles from days to minutes.
These metrics matter commercially because close automation is a category where expansion is typically driven by breadth of adoption across entities and processes. If Stacks is embedded in reconciliations and journal entries, it can become part of the control environment, raising switching costs and supporting multi-year retention.
Competitive dynamics: replacing legacy, not just adding a tool
Stacks is taking on platforms that often sit deep in finance stacks and integrate with core ERP systems. Winning competitive bake-offs here usually comes down to three practical factors:
- Implementation depth and time-to-value: finance teams will tolerate change if they can see measurable cycle-time reduction quickly.
- Reliability and auditability: automation must be explainable enough for controllers and auditors to trust it. Stacks’ emphasis on deterministic ML alongside AI agents appears designed to address that concern.
- Data unification: consolidating data across ERP and non-ERP sources is often the real bottleneck. A credible data layer can differentiate beyond workflow UX.
Stacks is also leaning into a broader market tailwind. The company frames its opportunity within the Office of the CFO software market, where digital transformation budgets are increasingly tied to provable productivity gains.
What the funding is likely to support
Stacks previously raised USD 10 million in 2025 from EQT Ventures and General Catalyst, which it said supported platform development. With a larger Series A now led by Lightspeed, the next logical step is scaling go-to-market and deepening product coverage, although the company has not detailed specific spending plans.
In enterprise finance, the sales cycle is rarely lightweight. Scaling typically requires building implementation capacity, a partner motion around systems integrators and ERP ecosystems, and tighter packaging for different complexity tiers (multi-entity, multi-ERP, global close). If Stacks can maintain the ROI outcomes it reports while expanding into larger, more complex rollouts, it can move from point wins to platform standardisation.
Lightspeed Partner Alex Schmitt said Stacks is “uniquely positioned to tackle some of the toughest challenges in enterprise finance,” citing the team’s expertise and traction.
What this enables
- Faster close and reconciliation cycles with measurable time savings
- Deeper automation across reconciliations, journals and reporting as adoption expands
- A stronger competitive push against established close and reconciliation incumbents
What to watch
- Proof that ROI holds in multi-entity, multi-ERP deployments
- Audit and controls acceptance as AI-driven automation expands
- Channel strategy: direct enterprise sales versus partners and integrators
- Product scope creep risk as it moves from close workflows into broader CFO platform territory