How do I set up Sage Intacct AR payment application?

Loopfour's Sage Intacct integration has a dedicated createArPayment action, separate from createApPayment, that applies an incoming customer payment against an invoice by its RECORDKEY. When a payment doesn't cover the full invoice, Sage Intacct applies it using the waterfall method — one unpaid line at a time, starting with the first — rather than splitting it evenly.

By Zuny Fester, Head of Operations and Marketing

Reviewed by Zuny Fester

Published September 14, 2026Last reviewed September 14, 2026Editorial policy

Part of the finance integrations guide.

Dedicated action	createArPayment, separate from createApPayment (AP has its own action)
How it targets an invoice	Invoice RECORDKEY plus TRX_PAYMENTAMOUNT
Partial payment behavior	Waterfall method — applies line by line starting with the first unpaid line until the payment is exhausted
Line-level targeting	Optional ENTRYKEY parameter to apply against one specific invoice line instead of the whole invoice

Why AR and AP payments are separate objects

Sage Intacct's API treats AR Payments and AP Payments as distinct objects — AR Payments record incoming customer payments applied to sales invoices, AP Payments record outgoing payments to vendors. Loopfour's Sage Intacct integration mirrors that split with two separate actions, createArPayment and createApPayment, rather than one generic "payment" action that has to be told which direction the money is moving. That's a real difference from NetSuite, which has no dedicated payment-application action at all for either direction, and from QuickBooks, which only exposes the AR side.

What createArPayment actually needs

At minimum, applying a payment to an invoice means specifying the invoice's RECORDKEY and the TRX_PAYMENTAMOUNT. For a payment that should land against one specific line on a multi-line invoice rather than the invoice as a whole, an ENTRYKEY parameter targets that line directly. Credits and discounts can be folded into the same call: a credit memo via ADJUSTMENTKEY, an inline credit via INLINEKEY, a custom discount via TRX_TOTALDISCOUNTTOAPPLY, and an overpayment via OVERPAYMENTKEY. A single request can also cover multiple customers at once by omitting CUSTOMERID and supplying PAYERNAME instead.

How partial payments get applied — the waterfall method

When a payment doesn't cover an invoice's full balance and no ENTRYKEY narrows it to one line, Sage Intacct applies it using the waterfall method: line by line, starting with the first line on the invoice and continuing down the list until each line is either paid in full or the payment amount runs out. That ordering is deterministic but not configurable per payment — a workflow that needs a different application order has to target lines individually with ENTRYKEY rather than relying on the waterfall default.

Next step

Map the finance workflow with the most exposure and prove the automation path.

Bring the invoice, contract, payment reconciliation, or customer finance workflow you have to defend at audit. Loopfour can map the trigger, controls, integrations, and approval loop.

Book a workflow review

Worked example

A $9,000 partial payment against a 3-line, $12,500 invoice

An invoice has three lines: $5,000, $4,500, and $3,000, totaling $12,500. A $9,000 payment arrives with no ENTRYKEY specified, so createArPayment applies it via the waterfall method: the first line ($5,000) is paid in full, the second line ($4,500) receives the remaining $4,000 and is left with a $500 balance, and the third line ($3,000) receives nothing. The invoice now shows $3,500 still open — not evenly distributed across all three lines, and not concentrated on whichever line happened to be largest or smallest, but strictly in the order the lines appear on the invoice.

Frequently Asked Questions

Not through the default waterfall behavior — that always starts with the invoice's first line. To control the order, target specific lines directly using the ENTRYKEY parameter instead of relying on the waterfall default.

Yes — credit memos apply via ADJUSTMENTKEY, inline credits via INLINEKEY, and overpayments via OVERPAYMENTKEY, all within the same action used for a standard payment.

It corresponds to the same underlying AR Payments functionality; Sage Intacct also has a newer ARPYMT object with draft-payment support that isn't the same as the legacy object this integration targets.

Sources

Topic

AR & Collections

Accounts receivable is the money customers owe a business for goods or services already delivered on credit — a current asset on the balance sheet until it's collected. AR and collections, as a practi…

How-to

How do I automate applying incoming payments to open invoices?

Match on an exact amount plus invoice reference first, auto-applying with no human involved, then use fuzzy or confidence-scored matching for near-misses like a payment short by a fee. Route anything that can't be matched confidently to an exception queue rather than guessing, and require an invoice reference at the point of payment wherever possible to maximize the automatic-match rate.

Topic

Integrations

Every finance automation vendor publishes an integrations page: a grid of logos, a claim of "seamless" connectivity, and not much else. That page answers a marketing question — does this vendor touch…

Diagnostic

What breaks when a Sage Intacct ArPayment goes unapplied?

If createArPayment is called with a RECORDKEY that no longer matches an open invoice line — the invoice was already partially paid, voided, or the line was adjusted between lookup and the call — the payment can be recorded without applying to anything. Cash arrives, but the invoice still shows as open and an unapplied balance sits on the customer's account instead.