Why Finance Teams Need Proper Approval Workflows (And Why Slack and Email Are Killing Your Controls)

Ask any finance manager how they handle spend approvals today, and you’ll hear a familiar story.

A bill lands in Xero. The bookkeeper screenshots it and drops it in a Slack channel. The manager sees it three hours later between meetings, replies “looks fine” with a thumbs up emoji, and the bookkeeper manually marks it approved. Somewhere, a spreadsheet gets updated. Maybe.

It works. Until it doesn’t.

This is how most small and mid-sized businesses run their financial approvals — and it is quietly one of the most expensive habits in modern finance.

Why Approval Workflows Exist in the First Place

Approval workflows aren’t a bureaucratic formality. They are a fundamental internal control — the mechanism that ensures money only moves when the right people have verified it should.

In accounting and finance, the principle behind this is called segregation of duties. No single person should be able to both initiate and authorise a financial transaction. One person raises a purchase order. A different person approves it. A third processes the payment. This separation exists to prevent errors, detect fraud, and maintain accountability.

Without a structured approval workflow:

• Unauthorised payments happen. A supplier invoice gets processed before anyone with authority has reviewed it.
• Fraud goes undetected. If one person can approve their own expenses or create and pay their own vendor, the opportunity for misappropriation is wide open.
• Errors compound. A duplicate invoice, an inflated amount, or a payment to a wrong account can slip through if there is no structured review step.

For businesses that are growing, seeking investment, or operating in regulated industries, these are not hypothetical risks. They are audit findings, compliance failures, and reputational damage waiting to happen.

The Hidden Cost of Approval by Slack and Email

On the surface, using Slack or email for approvals feels lightweight and practical. No software to set up. No new process to train people on. Just send a message and wait for a reply.

But the operational and financial cost is significant — and it compounds every month.

1. There is no audit trail

A “thumbs up” in a Slack message thread is not an audit trail. When your auditors ask who approved a $47,000 vendor payment and why, you cannot hand them a DM from eight months ago. Audit-ready approval records require timestamps, approver identity, the version of the document that was reviewed, and any comments or conditions attached to the approval. None of that exists in a chat thread.

2. Context gets lost immediately

Email and Slack approvals are contextless by design. The approver sees a dollar amount and a vendor name. They do not see whether this is the third invoice from this vendor this month, whether it exceeds the agreed purchase order, or whether the GL coding is correct. Without that context, approvals become rubber stamps — a formality rather than a genuine control.

3. Delays have real financial consequences

Finance teams operating on approval-by-Slack have no SLAs, no escalation paths, and no visibility into where a request is sitting. A payment run gets delayed because the CFO is travelling. A supplier charges a late payment fee. An early payment discount is missed. A contract renewal lapses. These costs are invisible in aggregate but add up meaningfully over a year.

4. The volume problem

At five employees, informal approval works. At fifty, it breaks. Finance teams at growing companies find themselves drowning in approval requests across multiple channels, with no systematic way to prioritise, escalate, or track status. The CFO becomes a bottleneck. The bookkeeper spends hours chasing responses. The whole process slows the business down.

5. Compliance exposure

For businesses subject to financial regulations — whether that is SOX compliance for US-listed companies, GDPR-related financial data handling, or simply a clean audit for investor due diligence — informal approvals are a liability. Auditors and investors expect to see documented, repeatable processes. “We approved it on Slack” is not a process.

6. There is no enforcement

Email and Slack approvals rely entirely on human discipline. There is nothing stopping a transaction from being processed before approval is received. There is nothing preventing the wrong person from approving. There is no system to enforce spending limits or escalation thresholds. The control only works when everyone follows the informal rules — which, under pressure, they often don’t.

What a Proper Approval Workflow Actually Does

A structured approval workflow is not about adding friction. It is about making the right thing the easy thing.

Done well, an approval workflow:

• Routes requests automatically to the correct approver based on amount, category, supplier, or department — without the requester having to know who that is.
• Provides full context to the approver: the invoice, the purchase order it relates to, previous transactions with this vendor, GL coding, and any relevant policy.
• Enforces limits and escalation — so a $2,000 expense can be approved by a department head, while a $50,000 commitment automatically routes to the CFO.
• Creates a complete, timestamped audit trail of every decision, every comment, and every document revision.
• Blocks processing until approval is complete — removing the risk of a payment being made before sign-off.
• Syncs back to your accounting software — so approved transactions are reflected in Xero or QuickBooks automatically, with no manual re-entry.

The result is faster approvals, stronger controls, and a finance team that spends its time on analysis rather than administration.

The CFO’s Perspective

Finance leaders often push back on approval workflow tools with a practical concern: “We’re not big enough to need this yet.”

But the right time to implement financial controls is before you need them, not after a problem has occurred. By the time an unauthorised payment, a fraud incident, or a failed audit makes the gap obvious, the cost far exceeds whatever friction was saved by staying informal.

More practically: if your business is growing, seeking external funding, or planning an exit, the quality of your financial controls will be scrutinised. Investors and acquirers look for documented, auditable processes. A business where approvals happen over Slack is a business with a due diligence problem.

Strong approval workflows are also a talent signal. Finance professionals who want to work in well-run organisations look for process maturity. A chaotic approval culture is a recruitment and retention risk.

The Bottom Line

Approval workflows exist because money is the area of a business most vulnerable to error, fraud, and mismanagement. Structured, documented, enforced approvals are not a luxury for enterprise companies — they are a baseline control that every finance team needs.

Slack and email are powerful tools. They are not approval systems. Using them as one creates audit risk, operational drag, compliance exposure, and a culture where financial controls are suggestions rather than guardrails.

If your team is still chasing approvals through chat threads and email chains, the question is not whether a proper workflow would help. It’s how much it’s already costing you not to have one.

ApprovalPro.ai is built specifically for finance teams using Xero and QuickBooks. It adds structured, auditable approval workflows to your existing accounting stack — without replacing it. Try it free →

• Approval Workflows
• Finance
• Accounting
• Internal Controls
• CFO
• Spend Management