Best Practices

How to Build an Expense Approval Workflow That Actually Works

5 min read Updated May 2026 For finance teams & managers

Most small companies handle expense approvals one of two ways: either there's no process at all (employees submit receipts and get paid, no questions asked), or there's a bureaucratic gauntlet that takes two weeks and three email threads to complete.

Neither works. The first invites abuse and accounting errors. The second frustrates employees and burns manager time. This guide explains how to build a middle ground — a workflow that's thorough enough to catch problems and fast enough that people actually use it.

Why Most Approval Processes Fail

62%
Of finance managers say their biggest challenge with expense management is lack of visibility into spending before it's approved.
Source: Certify Expense Management Survey
5.5 hrs
Average hours per week a finance team member spends chasing missing receipts, fixing errors, and following up on approvals.
Source: Aberdeen Group

The root cause in both cases is the same: no structured process. When approvals happen over email, things get lost. When there are no clear roles, nobody knows who's responsible. When there's no audit trail, there's no accountability.

The Two-Step Approval Model

The most effective pattern for companies with 10–200 employees is a two-step approval workflow:

1
Employee submits
Creates a report, adds expense lines with receipts and descriptions, and submits. The T&E approver is notified immediately.
2
T&E Approver reviews (manager)
Checks policy compliance — were expenses legitimate? Within limits? Properly documented? Approves or rejects with a comment. Finance is notified.
3
Finance approves (accountant)
Final sign-off. Checks categorization, GL codes, and total amounts. Approves and exports to accounting. Employee gets a confirmation email.

This separation matters. The manager knows the business context ("was this client dinner legitimate?"). Finance knows the accounting rules ("is this categorized correctly?"). Neither should be doing the other's job.

Roles and Responsibilities

Employee (submitter)

Responsible for: submitting expenses within the deadline, attaching receipts, providing clear descriptions, and responding to rejection feedback.

T&E Approver (direct manager)

Responsible for: verifying business purpose, checking policy compliance, and approving within 48 hours. Should reject with a reason if anything is unclear — not silently let things slide.

Finance / Accountant

Responsible for: final categorization review, GL code verification, and export to accounting. Should not be the first person to catch policy violations — that's the manager's job.

Common mistake: Giving Finance the role of both policy enforcer and bookkeeper. It overloads your accounting team and creates bottlenecks. Let managers handle the "should this expense be approved at all?" question.

What Good vs. Bad Looks Like

❌ Broken workflow
  • Expenses submitted by email to manager
  • Manager forwards to accounting@company.com
  • No receipt requirement stated anywhere
  • Approval communicated by "sounds good" reply
  • Reimbursement happens "whenever"
  • No audit trail if something is disputed
✅ Working workflow
  • Employee submits via app with receipts attached
  • Manager notified instantly, reviews in dashboard
  • Required fields enforced at submission
  • Approval recorded with timestamp and name
  • Reimbursement within 5 business days
  • Full audit log on every report

Setting Approval Limits by Amount

Not every expense needs the same level of scrutiny. A practical tiered approach:

Tip: Pre-approval for large expenses is the single biggest lever for controlling spend. It's much easier to say "this isn't in budget" before someone books a $3,000 flight than after.

How Long Should Approval Take?

48 hrs
SLA target for each approval step. If a manager hasn't reviewed within 48 hours, the system should send a reminder — not wait silently.
Industry standard for high-performing finance teams

Set an explicit SLA and communicate it. "Managers must approve or reject within 2 business days" is a reasonable standard. Include it in your expense policy so there are no surprises.

What to Do When Things Go Wrong

Employee submits the wrong amount

Reject the report with a clear reason. Don't edit it yourself — the employee needs to own the correction. A good system lets them reopen the report, fix it, and resubmit.

Missing receipt

Reject and ask for the receipt. If it's genuinely lost (a common claim for small amounts), require a signed declaration instead. Don't approve expenses without documentation — it creates precedent.

Policy violation

Reject immediately at the manager level with a reference to the specific policy clause. Don't let it get to Finance. If the same employee keeps violating policy, that's a conversation for HR, not accounting.

Building This Without Software

You can run a basic two-step workflow with email and a shared spreadsheet. Here's the minimum viable setup:

  1. Create an expense submission form (Google Form works)
  2. Responses go to a shared sheet (manager + finance both have access)
  3. Manager marks each row "Approved" or "Rejected" with a comment
  4. Finance marks approved rows "Paid" when reimbursed

It's clunky but it's a real process. The problem: there's no receipt storage, no notifications, no audit trail, and it breaks down above ~10 employees.

When It's Time to Automate

The inflection point is usually around 10–15 employees, or when your finance person starts spending more than 2 hours a week on expense management. Signs you've hit the limit of manual:

GreenLight handles all of this automatically

Two-step approval workflow, AI receipt scanning, QuickBooks export, and a full audit trail. Set up in under an hour.

Try free for 60 days →

Also read: The Complete Guide to Employee Expense Reimbursement →

Statistics sourced from Certify Expense Management Survey, Aberdeen Group, and GBTA Foundation research on SMB expense management.