How fast-growing e-commerce brands lose money through AP blind spots

Duplicate invoices, missed credits, wrong GST

There’s a moment most e-commerce founders remember clearly.
Revenue is up. Orders are flying. The brand finally feels like it has momentum.

And yet, the cash balance feels… off.

Not broken. Just constantly under pressure. Month after month, there’s a quiet sense that money is leaking somewhere, but nothing dramatic enough to trigger alarms.

That’s usually when accounts payable blind spots start doing damage.

Not fraud. Not incompetence. Just small, boring failures happening at scale. Duplicate invoices. Credits that never get chased. GST coded slightly wrong across hundreds of bills.

Individually, they barely register. Together, they quietly eat margin.

Let’s talk about how this actually happens inside fast-growing e-commerce brands, why it’s so common, and why “we’ll fix it later” almost never works.

The myth that growth exposes big problems first

Most founders assume scaling breaks big systems first. Warehousing. Logistics. Customer support. Shopify checkout.

But AP doesn’t snap. It bends.

Invoice processing still works… just not cleanly.

Bills get paid. Suppliers stay happy. The P&L doesn’t explode. So nobody looks too closely.

And that’s the trap.

AP blind spots don’t show up as fires. They show up as slow leaks.

Blind spot #1: Duplicate invoices that don’t look like duplicates

Duplicate invoices sound obvious. Same invoice number. Same amount. Same supplier.

In reality, they almost never look like that.

Here’s how duplicates sneak in:

• A supplier reissues an invoice with a new number after a minor change
• Freight invoices arrive once from the forwarder and again from the carrier
• An invoice is emailed, uploaded to a portal, and forwarded internally
• A credit note gets applied, then the original invoice is re-sent months later

Now add this to the e-commerce context.

High invoice volume. Multiple inboxes. Multiple entities. Different team members uploading bills at different times.

Suddenly “have we already paid this?” becomes a judgement call.

Most teams rely on memory, basic invoice number checks, or a quick glance at Xero or MYOB.

That works… until volume spikes.

Duplicates slip through because they aren’t exact matches. Same supplier. Same amount. Different reference. Slightly different date.

The system doesn’t flag it. Humans are busy. Payment goes out.

And nobody ever notices.

Until six months later. If at all.

Blind spot #2: Missed credits that never get followed up

Credits are the quiet killer of cash flow.

Overcharged freight. Returned stock. Incorrect quantities. Pricing adjustments. Damaged goods.

Credits usually start as an email thread, not a document.

“We’ll issue a credit next invoice.”
“Credit coming shortly.”
“Applied on your next statement.”

Then life moves on.

The AP team is processing new invoices. Bookkeepers are closing the month. Founders are chasing growth.

The credit never arrives. Or it arrives embedded inside a future invoice and gets missed.

Here’s the uncomfortable truth:
Most e-commerce brands don’t have a system of record for expected credits.

There’s no list that says:
• supplier
• amount owed
• reason
• status

So credits rely on human memory and goodwill.

At small scale, that’s fine.

At scale, credits quietly expire.

Suppliers aren’t being dishonest. They’re just busy. And if nobody follows up, nothing happens.

Money stays gone.

Blind spot #3: Wrong GST that compounds over time

GST errors rarely look dramatic.

They look like this:

• Freight invoices with mixed GST and no GST lines
• International suppliers charging GST incorrectly
• Customs charges treated as GST-free when they’re not
• Fuel levies taxed differently than base freight

A single invoice coded slightly wrong is no big deal.

But e-commerce brands process thousands of these.

And GST mistakes compound.

Over-claim GST, and you’re exposed at audit time.
Under-claim GST, and you’re bleeding cash every BAS.

The worst part? Most teams assume their GST is “mostly right”.

They trust templates. Reused codes. Old rules that no longer apply as supplier mixes change.

No one wants to re-open thousands of historical invoices to check.

So the errors stay buried.

Why fast-growing brands are especially vulnerable

Ironically, the better your brand is doing, the easier it is to miss these problems.

Here’s why.

Volume grows faster than process

Invoice counts double long before finance headcount does. What worked at 200 invoices a month collapses at 1,000.

Complexity increases quietly

New suppliers. New freight partners. New countries. New tax treatments. AP complexity creeps up without a clear “breaking point”.

Everyone optimises for speed

Founders want suppliers paid fast. Finance teams want inbox zero. Nobody is rewarded for slowing down to double-check edge cases.

Reviews get deferred

“Let’s clean it up after EOFY.”
“Once we hire a finance manager.”
“After the next funding round.”

That moment rarely comes.

The false comfort of “we’ll catch it in month-end”

Month-end feels like a safety net.

In reality, it’s a blunt instrument.

By the time month-end rolls around:
• The invoices are already paid
• The duplicates are buried
• The credits are forgotten
• The GST is locked into BAS

Month-end can catch big issues. It’s terrible at catching slow, repetitive ones.

And e-commerce AP problems are mostly repetitive.

Why tools alone don’t solve blind spots

Many teams already use invoice tools like Dext or Hubdoc.

They help. A lot.

But most were designed for document capture, not decision control.

They answer:
• “What does the invoice say?”

They don’t always answer:
• “Have we already seen something like this?”
• “Is this credit actually applied?”
• “Does this GST treatment make sense for this supplier and line type?”

So blind spots persist. Just in a nicer UI.

Where money actually leaks, line by line

Here’s what leakage looks like in practice.

• Paying the same freight cost twice across different entities
• Never receiving credits for damaged inbound stock
• Overpaying GST on non-taxable import charges
• Under-claiming GST on mixed invoices
• Missing volume discounts promised verbally
• Letting small discrepancies slide because it’s “not worth chasing”

None of these break the business.

Together, they quietly reduce margin.

Five figures a year becomes six. Six becomes seven as volume grows.

The uncomfortable question founders avoid

If someone asked you this, could you answer confidently?

“How much money did we lose last year from AP errors we never caught?”

Most founders can’t.

Not because they’re careless. Because the data isn’t visible.

AP blind spots are invisible by default.

What high-control e-commerce teams do differently

Teams that stop the leakage don’t rely on heroics.

They change how AP decisions happen.

A few patterns show up again and again.

They validate invoices, not just capture them

Invoices are checked against patterns, not just read.

Same supplier. Similar amount. Recent payment. That context matters.

They track expected credits explicitly

Credits become items with owners, not vague promises buried in inboxes.

They handle GST at line level, not invoice level

Freight, customs, fuel, duties. Each line gets treated on its own terms.

They surface exceptions instead of reviewing everything

Most invoices are fine. The few that aren’t should stand out immediately.

This is where modern bookkeeping AI and accounting AI workflows start to matter.

Not to replace humans. To focus them.

Why this matters more than ever in e-commerce

Margins are tighter. Freight is volatile. Advertising costs swing. Cash flow matters.

AP errors don’t just cost money. They distort reality.

Your P&L looks slightly worse than it should.
Your cash runway feels shorter.
Your decisions get made on fuzzy numbers.

Fixing AP blind spots doesn’t feel exciting.

But it’s one of the fastest ways to stabilise a growing brand.

No new ads. No new channels. Just less money quietly leaving the business.

The quiet upside nobody talks about

When AP blind spots disappear, something unexpected happens.

Finance feels lighter.

Month-end is calmer. Conversations with bookkeepers are cleaner. Founders trust the numbers more.

You stop second-guessing whether the problem is growth or leakage.

And that confidence changes how you scale.

If you’re a fast-growing e-commerce brand and any of this feels uncomfortably familiar, that’s a good sign.

It means you’ve outgrown manual AP without realising it.

And fixing that doesn’t require heroics. Just better visibility, better checks, and systems that notice the boring stuff humans miss.

That’s where the real money usually is.