If you run AP for an energy or industrial company on a custom internal accounting system with no cloud connector, and every AP platform you have evaluated has told you your situation is out of scope, this is written for you.
Here is what I shared on LinkedIn:
A petrochemical company recently came to us with a problem every other AP platform had told them was unsolvable.
They've been in operation since 1980, marketing aromatic feedstocks, olefins, gasoline blendstocks, heavy fuels, NGLs, and crude. Three hundred thousand barrels of storage. Product moving by pipeline, vessel, barge, rail, and truck. A finance operation processing several hundred bills a month against a completely custom internal accounting system that cannot connect to anything in the cloud.
The requirements they have for their bills is very specific. Every bill has to be decomposed into eleven distinct data fields before it can enter their system. Cost type from a fixed list of eight. An internal job number that their suppliers don't know and would never see. A separate flag for prior-period costs. A rebill structure that sometimes charges through at cost and sometimes marks it up and sometimes passes it to a party who isn't even the original customer. And at the end of all of that, a CSV is needed in precise, rigid column order that their legacy ERP will accept without kicking it back.
No other AP platform can do this. They are all built around the assumption that you are syncing into QuickBooks or NetSuite or Sage Intacct through a native API. Take away that assumption and they have nothing to offer you.
This is the part of the market we specialize in. Operationally complex businesses whose financial infrastructure is often decades older than the latest SaaS category, and who have no intention of ripping it out to accommodate an AP vendor. We meet the business exactly where it operates.
Why Every AP Platform Said No
Most AP automation platforms are built top-down: start with the accounting system integration and build the workflow around it. That architecture produces platforms that work well when the accounting system is on the supported list and produce nothing when it is not.
A petrochemical company that has been in continuous operation since 1980 is not on that list. Their accounting system is custom-built, internally maintained, and has no cloud connector. It does not need one. It works. Eight hundred bills a month move through it reliably. The problem is not the system. The problem is that no AP platform they evaluated was willing to meet them where they operate.
When the call opened, the prospect said: "I was hoping that maybe you might have a solution for us."
We did.
What the Requirement Actually Looks Like
Every vendor invoice needs to be decomposed into eleven distinct data fields before it can enter their system. Not extracted at the header level. Decomposed at the line level into fields the platform has to understand and populate correctly.
Cost type is one of those fields. It comes from a fixed list of eight categories. The platform has to read the bill, understand what kind of cost the line item represents, and assign the correct type from that list. Not a free-text field. A controlled vocabulary the system enforces.
Internal job number is another. Their suppliers do not know this number. It does not appear on the invoice. The platform has to derive or map it from other information on the bill and populate it correctly before the CSV can be generated.
Prior-period cost flagging. A rebill structure with three distinct charge-through scenarios: at cost, at markup, or passed to a third party who is not the original customer. Each scenario produces a different output in the CSV.
At the end of that workflow, a CSV file in precise, rigid column order. The legacy ERP accepts it or kicks it back. There is no error tolerance.
Why MakersHub Can Say Yes
MakersHub is built around the bill itself. The integration with the accounting system is a downstream output of the AP workflow, not the foundation of it. That architectural decision was deliberate. It means the output format is configurable to whatever the customer's system actually requires. A native API sync to QuickBooks. A CSV in rigid column order to a legacy internal ERP. We built it that way on purpose because the businesses that needed it most were the ones every other platform had decided were not worth building for.
The CSV export module works on incremental logic. It recognizes what is net new since the last export and exports only that. The column order, the field mapping, the cost type assignment, the internal job number derivation, the rebill logic: all configurable to match exactly what the legacy ERP expects to receive.
The Businesses That Get Told No the Most
The petrochemical and energy sector runs on financial infrastructure that predates the SaaS era by decades. So does a meaningful portion of industrial manufacturing, specialty chemicals, commodities trading, and heavy logistics. These businesses have been told repeatedly that their situation is out of scope, that they need to migrate to a supported platform, that their requirements are too specific to accommodate.
The requirements are not too specific. The platforms that said no were built for a different customer. MakersHub was built for the operationally complex business that the rest of the market passed on. Not because it is a niche. Because it is a real part of the economy that has been waiting a long time for someone to build for it properly.
We built MakersHub for the businesses the rest of the market decided were too hard to serve. If that is you, we would like to hear about it. makershub.com/get-started
Charley Howe, Co-Founder and President, MakersHub
Frequently Asked Questions
Can AP automation software work with a legacy internal ERP that has no cloud connector?
Yes. MakersHub exports a CSV in the exact column order your legacy ERP expects. The platform handles all the extraction, field mapping, and logic upstream so the file your system receives is already correct. You do not need to replace your ERP or add a cloud connector.
Why do most AP platforms fail for companies with legacy or custom ERP systems?
Most AP platforms are built around native connectors to QuickBooks, NetSuite, Sage Intacct, and Xero. If your system is not on that list, they have nothing to offer. MakersHub is built around the bill first. The accounting system integration is a configurable output, which means it works whether your system has a cloud API or expects a CSV in a specific column order.
What AP automation options exist for petrochemical companies with custom ERP systems?
MakersHub. We handle the full AP workflow: bill capture, field extraction, cost type assignment, internal job number mapping, prior-period flagging, rebill logic — and output a CSV configured to your exact ERP specification. We built this for businesses that have been told their requirements are too specific to support.
How does MakersHub handle custom CSV export for legacy ERP integration?
The CSV export module is incremental. It recognizes net new transactions since the last export and outputs only those records. Column order, field mapping, and all custom logic are configured to match what your system expects. The file either passes or it does not. We build to the spec your ERP requires.
What industries use MakersHub for AP automation with legacy accounting systems?
Petrochemical, energy, industrial manufacturing, specialty chemicals, and commodities businesses that process several hundred to several thousand invoices a month against internal systems that predate cloud software. These are businesses that have been told no by every other platform. That is the situation we built MakersHub for.