What Is Cash Application? How the Process Works, Step by Step

Why listen to us: ECIT Digital reads remittance advice in any format and matches payments to invoices for finance teams. Our AI does the reading, our people check what the AI is unsure about, and we guarantee 99.8% accuracy on the data we deliver.

Last month my friend Tom sent me $47 with the payment note "for the thing" [we have done many things together, Tom]. I spent ten minutes working out whether it was the pizza, the concert tickets or the drill he borrowed in 2023.

Congratulations, I had just done cash application, badly, for one payment. Your accounts receivable team does it for hundreds a day, with notes that are somehow even worse than Tom's. This guide explains what cash application is, how the process works, and walks through a real-looking example [Tom has not been told he is in a blog post].

Cash application terms at a glance

Cash application comes with its own vocabulary, most of it invented by people who really like the word "unapplied" [it is a lovely word, to be fair].

What is cash application?

J.P. Morgan defines it neatly: "Cash application is the process that ensures every payment is matched to the correct invoice in your accounts receivable records". In other words, a customer pays you, and you work out exactly which invoices that money closes [it sounds easy, which is how they get you].

It sits in the order-to-cash cycle right after collections, the team that chases the money. Collections gets the customer to pay, and cash application makes sure the payment lands on the right invoices, so nobody gets chased again for something they already paid. Few things annoy a customer more than a reminder for an invoice they paid last Tuesday.

You may also see it called payment application, which is the term the Association for Financial Professionals uses. It is also different from bank reconciliation, which ties your books to the bank statement. Our guide to invoice reconciliation covers that side.

The cash application process, step by step

Every cash application process, manual or automated, follows the same shape. The only difference is how many coffees it takes [manual: many].

Where the remittance comes from

The payment tells you how much. The remittance tells you what for. J.P. Morgan describes remittance advice as "a business document or electronic notification that accompanies an incoming payment", though in real life it often turns up separately, late or not at all [just like Tom].

The structured routes exist. X12 says the 820 "can be used to make a payment, send a remittance advice, or make a payment and send a remittance advice", and Nacha notes that a CTX entry "supports up to 9,999 addenda records". Our EDI invoice guide covers the X12 family in more detail.

But many customers never use them. In a Federal Reserve-backed Remittance Coalition survey from 2012, now old but still telling, 88 percent of companies received some remittance data in a document sent via email, fax, or paper. The Minneapolis Fed's Guy Berg later put it well: "Accounts payable and accounts receivable each focus on their own payments needs and are like two ships passing in the night".

A cash application example

Here is a small, made-up example with real-world mess built in. Our customer, Northfield Retail, has three open invoices [Northfield Retail is fictional, unlike Tom].

An ACH payment of $2,430.00 arrives. That is $50 short, which is the moment a cash application specialist puts the kettle on.

Then the remittance email arrives, with a PDF listing all three invoices and a note: "$50 deducted from INV-203, two units damaged." Now we can match it.

Without the remittance PDF, all you would know is "Northfield paid $2,430", which is about as helpful as "for the thing". The money would sit in unapplied cash until someone emailed Northfield to ask.

How payments get matched

Matching is a game of clues, and some clues are better than others [invoice numbers are the fingerprints, amounts are the "tall, brown hair"].

Good matching tries the strongest key first and falls back step by step, with tolerances for small differences such as bank fees. Anything it is not sure about should go to a person, not get guessed into the wrong invoice.

Short pays, deductions and unapplied cash

This is where cash application stops being data entry and starts being detective work [trench coat optional].

Unapplied cash is the one to watch. It makes customers look like they owe money they already paid, which leads straight to awkward reminder emails [the cash application version of asking Tom about the drill].

Why checks still matter in cash application

Checks were supposed to be gone by now, much like my 2019 resolution to stop buying gadgets. They are fading, but slowly.

In the 2025 AFP Digital Payments Survey, organizations reported that just 26% of their B2B payments are made by check, down from 33% in 2022. The Cleveland Fed counts it differently and found check's share of the number of B2B payments fell from 32 percent in 2015 to 13 percent in 2024.

Checks usually arrive through a lockbox, which J.P. Morgan describes as "specialized banking solutions that streamline your payment collection and processing workflow". The bank deposits the check and sends you an image and a file, but the remittance stub often still needs reading before anything can be matched.

How to measure cash application

If you cannot measure it, you cannot brag about it in the monthly review. Four numbers cover most of it.

For a DSO yardstick, APQC benchmarks from 2018 found that "At the median, companies need about 36 days to close the AR cycle", with top performers at 30 days or less. Cash application alone will not fix DSO, but slow posting makes it look worse than it is.

What software does, and what people still do

Cash application automation is good at the boring parts and should leave the judgement calls to humans [as should I, honestly].

The weak spot is usually the remittance, not the matching. If the invoice numbers are read wrong from a PDF, even perfect matching rules match the wrong thing. That is why we put a person behind the AI on anything it is unsure about. The same idea runs through our guide to document process automation.

As for Tom's $47: it was the pizza. I know because I finally asked, which is also the last step of every good cash application process [I am still waiting on the drill].