Rex for SAP
Rex runs collections, cash application, and disputes on top of SAP and writes the result back. SAP stays the ledger. Rex does not replace it, and it is the wrong buy if you want a suite implementation instead.
Rex runs collections, cash application, and disputes on top of SAP. SAP stays the system of record for the invoice, the customer, and the payment. Rex reads that ledger, does the follow-up and the exception work, and writes the result back. There is no migration off SAP.
Most teams go live in under two weeks. That figure is the general implementation claim on the site. It is not a SAP-specific customer story. The published customer, Synthesia, runs NetSuite.
What stays in SAP
SAP holds the financial record: open invoices, clearing, credit memos, and the customer master your close depends on. Rex does not stand up a parallel AR ledger beside it. Reports you already trust keep coming from SAP, provided the write-back is there.
Scheduled dunning inside SAP sends a notice because a date passed. It does not read the reply, pause a disputed line, or stop when the cash has already cleared. That work is what gets bolted on, and then retyped back into SAP, unless the layer writes it back itself.
What Rex runs on top
- Collections. Every open invoice followed up. A promise moves the next touch. A dispute pauses the contested amount.
- Cash application. Payments matched to SAP open items, including short pays. The remainder stays open and is either collected or coded as a deduction.
- Disputes and deductions. Evidence gathered and the case moved, with the status written back so SAP aging is not a week behind the argument.
- Customer AP portals. Buyers on SAP Ariba, Coupa, and the rest still require their own submission rules. Portal work is a separate job from the SAP ledger. Rex does both, and they meet in the write-back.
The objects that have to sync both ways are open invoices, payments, credit memos, customer data, promises to pay, and dispute status. An export that only leaves SAP is a second system someone has to reconcile.
When Rex fits, and when it does not
Rex fits when SAP is the ledger you are keeping, and the constraint is labor on collections, cash application, and exceptions. Agents do that work. Your team and a Rex finance expert take the cases that need a person.
Rex does not fit a team that wants SAP-native dunning only. It does not fit a company buying one suite to cover credit, billing, treasury, and record-to-report. HighRadius and Esker are the vendors that comparison usually includes, and they are the better buy when the project is the suite. See order-to-cash software vendors and HighRadius alternatives.
The same layer on other ledgers is NetSuite and Oracle Fusion.
Frequently asked questions
- Does Rex replace SAP?
- No. SAP stays the system of record. Rex reads invoices, customers, and payments from SAP and writes collections activity, applied cash, promises to pay, and dispute status back. There is no migration off SAP.
- How is Rex different from an order-to-cash suite on SAP?
- A suite such as HighRadius or Esker is a platform your team configures and operates across the cycle, often in a long implementation. Rex runs the working steps, collections, cash application, and disputes, on the SAP ledger you already have. A suite is the better buy when you want one vendor for credit, billing, treasury, and record-to-report.
- Does Rex work with SAP Ariba?
- SAP Ariba is a customer AP portal, not the ERP. Rex submits invoices and retrieves purchase orders on Ariba and other buyer portals. The published Synthesia story includes Ariba alongside NetSuite, and that customer runs NetSuite, not SAP. This page is about SAP as the ledger.