Your ledger stores the result of the work. It is not where the work happens, and replacing it is the most expensive available way to avoid the problem you actually have. What that problem is, and what to settle before you automate anything on top of it.
"The contract is not the legal matter, the ticket is not the customer's resolution, and the opportunity is not the sale."Seema Amble, Andreessen Horowitz, on why the record a system holds is not the job its users are doing · Sep 2026
AI-native ERP became the answer before anyone checked which question the models had actually solved.
In August 2026, Rillet raised a $100M Series C at a $1B valuation, led by ICONIQ with Sequoia, Andreessen Horowitz, Bain Capital Ventures, Battery and others alongside. The company describes its platform as an AI-native ERP built to rebuild the general ledger from scratch, and names NetSuite, SAP, Workday and Oracle Fusion as what it displaces. It is a serious product with more than 600 customers and revenue that has doubled twice in six months. This is not an argument that the company is wrong about its own business.
It is an argument that the category is the wrong shape for the buyer, and that the label attached to it has been doing a lot of quiet work.
Start with what changed in the models, because the category was named after that change and does not match it. Models did not get better at storing financial state. Storing state correctly and durably was solved decades ago, and it was never the constraint. What changed, over roughly the last twelve months, is that a model can now run a long sequence of steps across several systems, discover something in step forty that invalidates an assumption from step six, branch, reconcile and keep going without falling over. Long-horizon execution across software is the capability that arrived.
That capability describes the work that produces a journal entry. It does not describe the journal.
Buying an AI-native ERP takes the problem that was already solved, pays the highest displacement cost in your stack to solve it again, and leaves the problem the models just cracked exactly where it was.
Every one of those steps happens outside the ledger, in the billing system, the CRM, the bank portal, the contract repository, the spend management tool and the workbook where someone ties it all together. The ledger receives the last step. Automating the last step is not the opportunity, because the last step was already automated.
SAP is complicated for a reason, and the reason is roughly eleven modules that have nothing to do with accounting.
SAP S/4HANA ships about a dozen core functional modules. Finance and Controlling, Sales and Distribution, Materials Management, Production Planning, Quality Management, Plant Maintenance, Project System, Human Capital Management, Supply Chain, Customer Relationship Management, Environment Health and Safety, and then industry-specific extensions on top of those. The general ledger is one component of one of them. NetSuite is complex for the same reason, and so is Oracle Fusion.
The products currently marketed as AI-native ERPs rebuild the ledger. That is what their own materials say, and it is a reasonable thing to build: the accounting core of most mid-market finance stacks genuinely is dated, and an agent-first close is a real improvement over manual journal entry. The problem is the word wrapped around it.
If your company runs on a ledger and not much else, a modern ledger is a sensible purchase and you should evaluate one. If you carry inventory, run projects, plan production, hold several legal entities, file statutory reports in more than one country or depend on procurement and warehouse logic that has been tuned for fifteen years, then what is on offer covers a slice of what you have and none of what makes replacing it hard. The modules you never think about are the ones that surface on the Monday after cutover.
Being precise about this matters at the point of purchase, because "we are replacing your ERP with AI" and "we are replacing your general ledger with AI" are proposals with different risk profiles, different scopes and different prices, and only one of them is being described accurately.
SAP customers moving to SAP, with the vendor's own tooling and a deadline forcing the issue, are running past the deadline.
SAPinsider's April 2026 benchmark found 55% of organisations claiming an S/4HANA deployment and 34% fully transitioned, with somewhere between 20,000 and 25,000 legacy SAP ERP customers not yet licensed for the target platform at all. The 2027 maintenance deadline is cited by 39% of them as a reason to move, and AI announcements by 43%.
Holger Scheel of cbs Corporate Business Solutions told CIO that roughly half of large and midsize industrial companies have started the transformation and "very few have completely finished it", and that 2030 is the more realistic target for the rest. He puts the delay down to ERP systems that grew organically over twenty years, with correspondingly complex data structures. The standardisation work turns out to be much larger than the migration work anyone scoped.
Those are migrations from one vendor to the same vendor, with that vendor's tooling, its partner network, a global consulting industry organised around the task and a hard maintenance cutoff pushing everyone forward. They are still slipping by years. A move to a different vendor with a narrower functional footprint is not the easier version of that project.
Then weigh what the project buys. You inherit the durability, controls and implementation burden of the system with the highest displacement cost you own. And on the far side of it, your CRM, billing system, payroll provider, banks, spend management tool, contract repository and warehouse are all still running, still holding numbers finance has to reconcile against the new ledger, and the work of reconciling them has not moved an inch. You paid the largest bill available and the actual work was not in scope.
A journal entry is what survives the work. Everything that made it correct happened somewhere else.
A journal entry states an amount, an account, a date and a currency. It does not state which of three source systems was trusted when they disagreed, what failed to tie and how the break was resolved, which policy election constrained the treatment, what precedent from last quarter applied, what the controller changed on review, or what evidence closed the exception. All of that happened. None of it is in the record.
That is not a design flaw. A ledger is meant to be a compact, auditable statement of position, and a hundred fields of provenance per line would ruin it at the job it exists to do. But it does mean the ledger is a poor place to look for the work, and a worse place to put an agent whose value depends on doing the work well.
Seema Amble made the general version of this argument at Andreessen Horowitz in September 2026, writing that "the contract is not the legal matter, the ticket is not the customer's resolution, and the opportunity is not the sale." Her conclusion is that incumbents holding the record get stronger as agents get more capable, because the data and actions they control become more valuable, and that the durable opening is for whoever becomes best at doing the job across systems rather than owning any one record.
The companies building in this category understand that. Rillet does not describe a passive book of record. It describes agents performing accounting work, native integrations pulling operational data in, accounting policy and controls applied alongside that work, and an audit trail over what the agents did. Almost all of that describes the layer around the ledger rather than the ledger itself. What is left open is whether owning that layer requires replacing the system of record underneath it.
For anyone holding a budget, that resolves into a short instruction. Keep the record. Buy the work.
Two thirds of finance teams do their reconciliation in Excel, and every one of those companies already owns a ledger.
BetterCloud's 2026 State of SaaS report puts the average company at 118 SaaS applications, up 11% on the 106 recorded a year earlier, which reverses two years of consolidation. Companies with 1,500 to 4,999 employees went from 116 applications to 164 in a single year. Each of those holds some state that finance eventually has to reconcile, and the count is rising rather than falling.
The clearest evidence that the work sits outside the ledger is what finance teams reach for when they need to get something done. Odoxa surveyed 303 CFOs at UK private companies with 250 or more employees on behalf of Sixthfin in May 2026. Two thirds use Excel for account analysis and reconciliation. 57% use spreadsheets for accruals, 54% for manual journal entries, 53% to run the close calendar. More than a third say they do not have high confidence in the reliability of their own figures, and 97% say the monthly close affects workload across the team.
Every one of those companies has a general ledger, and most of them have a good one. The spreadsheets are not there because the ledger is bad at being a ledger. They are there because getting to a defensible number spans systems the ledger does not reach, and the workbook is the only place that work has ever been allowed to happen.
Replace the ledger and the workbooks stay exactly where they are. That is the test to apply to any proposal in this category: after the migration, does the Tuesday of close week look different? If the reconciliation still runs in Excel across six systems, you bought a nicer ledger.
Put a capable agent above the systems you already run and you avoid the cutover. You have not yet finished the job.
Suppose you take the other route. The ledger stays, the CRM stays, the billing platform stays, and a capable agent goes above all of them. Published APIs, MCP servers and modern integration tooling make that access cheaper every quarter, so the agent can read every number the analyst could read and nobody spent three years on a migration to get there.
That is the better architecture. It is not yet a working one.
Reaching the data is a different thing from understanding it. The agent inherits all the information the analyst had and none of the judgment the analyst applied to it, and the space between those two is where answers go wrong. An agent with read access to six systems and no instruction about which of them is authoritative for a given figure will still return a number, confidently, in the format you asked for. Adding a seventh connector does not change that.
Both routes arrive at the same unsolved problem. The migration just charges more to get there.
Connecting a model to a hundred systems is the easy half. The systems disagree about what the words mean, and nobody wrote down which one wins.
What does not get cheaper with better connectors is that each of those systems carries its own definition of the same word, and the definitions are all defensible.
Revenue in the billing system is what was invoiced. Revenue in the CRM is what was booked. Revenue in the close is what was earned in the period after the deferral rules run. A customer is a logo in the CRM, an account in billing, a workspace in the product and a legal entity in the ledger that may hold several of each. An active user is a login in one system and a paid seat in another. None of these is wrong. Each was defined by a competent person for a purpose that still holds today.
An experienced analyst navigates all of it silently. They know the sales figure excludes intercompany, that the finance figure applies the deferral, that the two customer counts differ by four percent for a reason someone settled in 2021. That knowledge was never written anywhere a machine can read, because until now it never had to be. It sat in the room with the person doing the work.
Take the person out of the loop and the missing definition stops being an inconvenience and becomes the output. An agent asked to reconcile across five systems has no way to discover which definition applies where. It will choose one, it will be confident, and the answer will look exactly like a correct answer. A wrong number that looks wrong gets caught in review. A wrong number that looks right gets presented to the board.
One system means one definition, so collapsing your systems looks like it collapses the disagreement. It does not. The disagreement was never inside the ledger.
This is exactly why the replace-the-ledger pitch is appealing, and exactly why it fails. The disagreement lives between the ledger and everything upstream of it, which a ledger migration leaves untouched. And you are not going to end up with one system anyway: the SaaS count per company is going up. Whichever route you take, somebody still has to decide what the words mean.
A finance lead asks an agent what revenue was for Germany last quarter. The question sounds like a lookup.
It is not a lookup. Before anything can answer it, somebody has to have settled all of the following.
None of those is exotic. Every one of them was decided by somebody at some point, and most were never written down. The last two are the ones companies discover late. Sales can legitimately need bookings while finance needs recognised revenue, and the answer is not to average them into a figure neither will defend. It is to keep both, record which question each one answers, and know how they reconcile.
A glossary or a data catalogue can hold all of that, and holding it beats not holding it. But a document and an executing system are two different things. Change the query next month without changing the glossary and the two drift apart quietly: the documentation still reads correctly while the system returns a different number, and nothing in the process notices.
So for an agent, meaning has to be executable. The alternative to a migration costs far less and is considerably less pleasant, because it is not a purchase. It is a decision. Somebody has to say what your company means by revenue, by customer, by active, by an expense, and where each legitimate variant applies. Then that has to live somewhere an agent can read and somewhere it cannot quietly rot: executed as code the query engine runs, versioned, owned by you, with a named person who signs off when it changes.
Two properties follow from doing it that way. Answers become reproducible, because meaning gets resolved once at indexing time rather than re-guessed inside a model on every query, so the same question against the same data returns the same number today and next quarter. And the layer survives your model choice, which almost nothing else in your AI stack does. If the only place your business logic exists is a model provider's context window or memory service, your institutional knowledge is rented, and switching vendors becomes an amnesia event rather than a procurement decision.
A spend management platform sitting upstream of its customers' ledgers, where none of the rules had ever been written down.
One of our customers is a spend management platform. Its own customers are finance teams, and everything it holds, meaning expenses, budgets, approvals and invoices, is upstream of their ledgers. Before any of it becomes a journal entry, a chain of judgments has already been applied: which expense types and statuses count, which cost centre, which period, which exchange rate from which day, how to treat an amount that spans several months. That chain is the work. The entry is what is left of it after the work is done.
None of those rules existed in writing.
We connected read-only to their MongoDB and generated the structural layer automatically, because their tables carried no descriptions. They named the first five reports they wanted and wrote a short brief for each. The output had large gaps against what they expected, and the gaps were the useful part: a brief describes what you want, not the rules underneath it. So they sent us the queries behind their existing reports, we reverse-engineered the logic out of them into a written reference, and then spent a week with their team on what the queries could not explain by themselves.
Two things came out of that week.
The first was a rule that had never been decided at all. How should a performance period be assigned when an amount spans several months? Nobody had ever specified it, and their own system had been applying it differently from one report to the next.
The second was less comfortable. Two legacy reports, built three years apart by different engineers, returned different numbers for the same figure, one of them carrying a hardcoded condition with no explanation attached. Neither engineer had been careless. Nobody had ever decided which reading was right, so both shipped.
Once the logic existed as definitions rather than as code buried inside individual queries, five things changed.
Nothing in that programme needed a new ledger. Their accounting systems were fine and stayed where they were. What was missing was a written, executable statement of what their own numbers meant, and until it existed, nothing built on top could be trusted, whether the thing on top was a report, an agent or a person.
Three requirements for an AI system doing work a company will act on, and where each one has to live.
Systems of record are not going away, and in an agentic setup most of them get more valuable, because they remain the authoritative place where state and actions are held. What changes is what has to exist across them. An AI system doing work a company will act on has to reach information wherever it lives, understand how the concepts in those systems relate to one another, and produce results somebody can explain afterwards. At LazyFox we treat those as three separate problems.
Data is the access problem: can the system read the relevant information across the stack you already run, without a migration as the first step. Meaning is the interpretation problem: does customer, revenue, active or expense resolve to the right definition when five systems encode the concept differently. Trust is the production problem: can the company see where an answer came from, which definition applied, what the person asking was allowed to see, and why the result held at that moment.
The component that reconciles all three is what we call the Enterprise Intelligence Layer. It runs across the systems a company already has and serves their meaning to whichever application or agent is asking. LazyFox is broader than that layer. We are building an Enterprise AI Adoption Platform around one problem: getting AI from pilot into production without asking the company to rebuild its technology estate first. It connects read-only to the existing stack, and no migration is the entry price.
That is also the test to put to the new finance platforms. Whether an AI-native ledger can beat a fifteen-year-old ledger is not in dispute; it can, and for a company whose accounting core needs replacing anyway there is real appeal in having the ledger and the automation built together from day one. Whether the new capability has to arrive attached to a ledger replacement is a separate question, and for an enterprise with years of controls, integrations and business logic embedded in SAP or Oracle, the two do not have the same answer.
As models get more capable the value moves to the context, policies and decisions that connect the applications. That layer belongs to the company that runs them, not to whoever sold one of them.
None of that context belongs naturally to Salesforce, to SAP, to the bank, to the billing platform or to whoever supplies the model. It is the accumulated result of how your company decided to operate, and it is the one part of the stack you cannot buy back after giving it away.
Seven things to settle, none of which requires migrating a system of record.
None of this expires when the models change. A definition of revenue that finance, sales and delivery have agreed on is still correct whether it is read by a model shipping today or one shipping in three years. Most of the rest of your AI stack is rented on terms that change every few months.
Seven lines for anyone who scrolled.
AI-native ERP solves the wrong problem for what AI changed in finance. An ERP exists to hold financial state durably, and models did not get better at storing state; they got better at executing long sequences of steps across many systems. Most products marketed as AI-native ERPs rebuild the general ledger, which is one component of one module in a system like SAP S/4HANA. Replacing it means the largest migration in the stack while leaving the cross-system work untouched: 67% of UK companies with 250 or more employees still reconcile in Excel, and the average company runs 118 SaaS applications.
The post argues that what actually blocks cross-system automation is meaning rather than connectivity. Billing, CRM and the financial close each hold a defensible and different definition of revenue, and the rule for which applies where was never written anywhere a machine can read. It walks through the nine decisions sitting behind a question as ordinary as revenue for Germany last quarter, why definitions belong in versioned code the company owns rather than in a glossary beside the system, and what this looked like at a spend management platform where two legacy reports had returned different numbers for the same figure for three years. It closes on the three requirements LazyFox separates out, data, meaning and trust, and why skipping the migration and putting an agent above the existing stack still leaves the definition problem unsolved.
LazyFox holds your business definitions as versioned code your company owns, and serves them to whichever model or agent is asking. It connects read-only to the systems you already run. Nothing migrates.