When setting up expense management for your business, the easiest option is often the one that’s already built into your existing software. Most accounting systems, ERP platforms, and HR tools come with an expense management bolt-on as standard. It’s there. It’s included. And if you’re already using Xero, Sage, NetSuite, or Hibob, it feels like the logical choice.
For small teams with straightforward expense needs, these modules can work perfectly well. But as your business grows – as expense volumes increase, as policies become more comprehensive to cater for operational scale, as you need better reporting and tighter controls – the limitations of a bolt-on expense software solution really start to show.
The question isn’t whether you need expense management. Instead, the question is whether a general-purpose add-on will serve you long-term, or if you need something purpose-built for the job.
This guide explains the difference, where bolt-ons fall short, and when it makes sense to invest in a dedicated expense management solution (like Webexpenses!).
What is a bolt-on expense module?
Okay, let’s define our terms here first, since you might not actually know what a ‘bolt-on’ refers to. Simply put, a bolt-on expense module is an add-on. It’s a feature that sits within a larger platform.
You’ll find these in three main categories:
- Accounting systems with expense modules: Xero and Sage both offer expense tracking as part of their accounting suites. They’re built to help you record expenses for bookkeeping purposes, but they’re not designed to manage the full expense lifecycle. You can log a receipt, categorise it, and export the data, but don’t expect sophisticated approval workflows, policy enforcement, or mobile-first functionality.
- ERP systems with expense add-ons: Platforms like NetSuite and Microsoft Dynamics offer expense management as part of their broader enterprise resource planning tools. These are more robust than accounting software bolt-ons, but they’re still secondary to the core product. Implementation can be lengthy, customisation is often complex, and the user experience tends to reflect the fact that expense management wasn’t the primary focus when the system was designed.
- HR platforms with expense features: Tools like Hibob and Personio have added expense management to their HR suites. The idea is simple: keep everything in one place. But in practice, these modules are usually fairly basic. They’ll handle simple reimbursements and track who’s claimed what, but they lack the depth you’d get from a dedicated solution. Mileage tracking, VAT reclaim, corporate card reconciliation, and fraud detection often feel like they’ve been tacked on rather than thought through.
And that’s just the curated list. There’s more expense modules out there, nestled inside all sorts of Trojan Horses.
The appeal of these bolt-ons is obvious. You’re already using the platform. You don’t need to introduce a new tool. Your team doesn’t need to learn another system. And at first glance, it seems like a sensible way to keep everything consolidated.
But consolidation isn’t the same as optimisation.
Where bolt-ons fall short
The problem with expense management bolt-ons is that they’re built to serve the parent platform, not your expense process. That means compromises.
Limited functionality:
Most bolt-ons cover the basics: submit a receipt, get it approved, record it in your ledger. But what about duplicate claim detection? Intelligent receipt matching for corporate cards? Automated mileage verification? Real-time policy enforcement? These aren’t luxuries. They’re the tools that prevent overpayments, reduce admin time, and stop fraud before it becomes a problem. And they’re rarely included in bolt-on solutions.
Poor user experience:
Accounting and ERP systems aren’t designed with the everyday user in mind. They’re built for finance teams who understand general ledgers, chart of accounts, and double-entry bookkeeping.
So when you ask a sales rep to log their expenses through an ERP bolt-on, you’re essentially asking them to navigate a system that wasn’t designed for them. The result is frustration, errors, and expense claims that sit uncompleted because the process is too cumbersome.
Mobile limitations:
Your employees aren’t submitting expenses from their desks. They’re doing it from taxis, hotel lobbies, and airport lounges. A purpose-built expense management solution understands this and builds the experience around mobile-first functionality. Bolt-ons, on the other hand, are often desktop-centric. If there’s a mobile app at all, it’s usually clunky, limited, and clearly an afterthought.
Weak policy enforcement:
A good expense system doesn’t just record claims. It enforces your expense policy automatically. It flags out-of-policy spending in real time. It prevents duplicate submissions. It ensures VAT is captured correctly.
Bolt-ons rarely have this level of sophistication because policy enforcement isn’t their priority. The result is more manual checking, more errors, and more time spent chasing people for missing receipts or incorrect claims.
Integration challenges:
This might sound counterintuitive. After all, if your expense module is sold as part of your accounting or ERP system, surely it integrates seamlessly? Not always. Many bolt-ons still require manual data transfers, CSV exports, or workarounds to get information from one part of the system to another.
Even when the integration with the parent system works smoothly, bolt-ons face another limitation: they’re really only optimised to work with their mothership. Unlike standalone products that prioritise connecting to multiple platforms, bolt-ons focus narrowly on serving the central software suite.
Slow to innovate:
When you’re using a bolt-on, you’re relying on the parent company to prioritise expense management in their product roadmap. And the reality is, they won’t.
Accounting software companies focus on accounting. ERP providers focus on resource planning. HR platforms focus on people management. The focus is always on ‘core’ functionality.
An edge functionality (like expense management) will always be somewhat neglected. It’ll get updated when there’s time (hint: there’s never time), which means features lag behind, bugs take longer to fix, and you’re stuck with a tool that doesn’t evolve with your needs.
You might find yourself manually updating mileage rates every tax year, waiting months for a critical integration, or working around clunky receipt capture because it’s simply not a priority for the vendor
Why purpose-built expense management exists
When your company begins expanding and expense volume increases, using a bolt-on is like using a butter knife to cut a steak.
Expense management is complex, and doing it well requires focus. It’s not a side feature. It’s a full discipline that spans policy design, user experience, fraud prevention, compliance, reporting, and integration.
A purpose-built solution like Webexpenses is designed around the entire expense lifecycle. From the moment an employee snaps a receipt on their phone to the moment the claim is approved, reimbursed, and recorded in your accounts, every step is optimised. Faster processing, fewer errors, better compliance, and your finance team is freed up for value-added work.
It also means the system evolves with you. When regulations change, when your business expands internationally, when you need to enforce new policies or integrate with new tools, a standalone expense management system adapts quickly.
Take HMRC’s advisory EV mileage rates. In September 2025, HMRC introduced new advisory rates for EVs that vary depending on where the vehicle was charged – at home or on a public network.
This added complexity for businesses with company-owned EVs. When HMRC announced the change with only days’ notice, Webexpenses adapted quickly to complete the development and release in time to be compliant, handling both rates with no manual intervention needed for our customers.
How quickly would your accounting software’s expense bolt-on have adapted to that level of complexity?
Working with us, you’re not waiting for an accounting software company to add expense features to their next update. You’re working with a provider whose entire focus is making expense management as efficient and accurate as possible.
What you get with a dedicated expense system
| Benefit | What it means for you |
| Speed | Employees submit claims in seconds through our app. Approvers process claims on the go. Reimbursements are simplified (or, if using our Expense Cards, eliminated). |
| Accuracy | Duplicate detection and intelligent receipt matching eliminate the most common sources of error. VAT is captured and ready to export for your returns. Mileage is calculated accurately. |
| Control | You define your expense policies once, and the system enforces them automatically. Out-of-policy claims are flagged or blocked. Spend limits are applied. Suspicious claims are flagged before they’re paid. |
| Visibility | Real-time dashboards show you exactly where your money is going. Track top spending categories, top spenders by division, and accumulated mileage. See out-of-policy approvals, monitor claim processing times, and forecast future spend based on historical data. All filterable by time period and customisable to your needs. |
| Integration | A dedicated system integrates with your existing tools. Whether you’re using Sage, Xero, NetSuite, or another platform, your expense data flows seamlessly into your accounts without manual intervention. You get the best of both worlds: a specialist tool for expenses and a smooth connection to your broader finance ecosystem. |
When a bolt-on might be enough
To be clear, not every business needs a dedicated expense management system. If you’re a small team with minimal travel, simple reimbursement needs, and no complex approval workflows, a bolt-on might serve you perfectly well. If your expense volume is low and your policy is straightforward, the limitations of a basic module might not matter.
But if you:
- Process dozens or hundreds of expense claims each month.
- Manage corporate cards or need Expense Cards.
- Have employees in multiple locations.
- Need to enforce spending policies and track VAT.
- Simply tired of the manual work involved in managing expenses.
Then, the choice is really clear: You need a best-in-breed expense management solution that will save you time, money, and a lot of frustration.
See for yourself what a dedicated expense solution can do. Book a free demo and discover how Webexpenses can transform the way you manage expenses.
