How to enhance data insights: Custom expense fields & categories

It's 2025, and you need your expense tracking system to work for your organisation's specific needs. That means being able to customise things like expense fields or expense categories. You need access to data that's going to drive real change in your organisation, and the best way to ensure this data is accurate and granular is to use custom expense fields and expense categorisation.

No two businesses are the same, so the first step towards better data insights and spend management is an expense management system that works for you on a granular level.

The role of custom expense fields and categorisation in data analysis

Categorising your expenses into broad groups like operational, capital, or ‘miscellaneous’ is a good start towards better data analysis — but it’s not enough if you want truly detailed insights into how your organisation spends.

That’s where custom expense categories and custom fields come in. For example, creating fields that reflect your organisational structure — such as categorising expenses by department or location — allows you to pinpoint precisely where and how your teams spend, highlighting unnecessary spending patterns and giving you a clearer picture of where to optimise costs at a departmental level.

On the other hand, having fields like project ID or location also makes it easier to analyse spending in greater depth. Knowing, for instance, which expenses contribute most to a particular project can empower you to adjust and optimise your project budgets moving forward.

Without this level of customisation? You’ll be stuck manually sifting through expense data, trying to compare, identify patterns, and uncover insights.

The good news is... you can customise expense fields and categories with a spend management solution like ours at Payhawk. Our solution automatically reconciles your accounts with your ERP via smart integrations, pulling through your master data to make data analysis both effortless and seamless across systems.

How custom expense fields and categories improve data analysis

Customising your expense fields gives you unparalleled control over spend. Here are four main benefits of using features like this in expense management:

1. Improved accuracy in expense reporting

By customising expense fields and categories, you have better control over your data; you can generate more detailed reports, which means you can spot spending patterns and reallocate resources and team budgets for specific projects.

2. Enhanced budget forecasting

Knowing exactly what you've spent and who's spent it makes budgeting a lot easier. You have better insight into spend, broken down by however you want to categorise it, i.e., by department, GL code, or any custom field. So you can adequately manage cash flow and forecast for long-term growth.

3. Easier identification of tax-deductible expenses

By categorising and sub-categorising expenses, you can easily note which expenses are tax deductible and which aren't. This streamlined process ensures your tax bill is accurate and you're not paying HMRC over the odds.

For example, German automotive giant ATU improved reconciliation and saved over £2 million from the tax office by simply implementing digital expense reporting for managers via Payhawk. After taking a picture of the receipt or invoice, data is automatically pulled into the spend management system, reconciling transactions in real time.

4. Better visibility into departmental spending

If you notice one particular department is spending more than others, you can investigate their spending easily by categorising and exporting the data for closer examination. These insights help you quickly identify suspicious activity and nip unnecessary spending to protect budgets.

So, if you have multiple departments, locations or venues, like State of Play Hospitality (Flight Club, Bounce, and more), being able to customise how you split and analyse spend is essential. Andrew Jacobi, VP of US Finance at State of Play Hospitality, says:

We rely on the customisable class settings within Payhawk to distinguish between venues and analyse performance. Whether it's categorising between venues or categorising it into the right general ledger code, it's extremely helpful in terms of how we allocate spend.

Best practices for implementing custom expense fields and categories

To get the most out of custom expense fields, it's not just about setting them up — it's about managing them effectively. From making it easier for employees to categorise expenses correctly to ensure your system stays up-to-date as your business evolves, there are a few best practices that can help maximise the value of your data. Here's how to keep your expense fields working hard for your business:

• Make it easy for employees to choose the right custom fields. It's all well and good to introduce these custom fields, but if your employees don't categorise expenses correctly, your data won't generate as much value as it could have. Having a system that allows you to set up user-friendly names that automatically map to the right general ledger accounts is crucial.
• Regularly review your expense fields. If you're a scaling business, you'll need to create new teams and hire more employees, so your fields and categories will need to change. Build a regular review cycle into your calendar, address changes, and make amends to keep it working as smoothly as possible. And choose a system that integrates with your ERP correctly so you only have to make those changes once.
• Integrate your spend management with accounting software. By integrating your systems, you remove any chances of duplicate or missing transactions, all data is accurate, and everyone is accessing a single source of information, which is crucial when making strategic business decisions.
• Use the data you get to make actionable decisions. Being able to access this data is essential, but it's what you do with your findings that matters most. Accurate data gives you the power to make confident, well-informed decisions to set your business up for success both with short-term and long-term focus — so use it.

And don't forget the big and vital step before you create your expense categories: Managing your master data (including across multiple entities).

How to manage master data and custom fields across multiple entities

1. With Payhawk, you can centralise and consolidate your master data and custom fields at a group level to ensure accurate, aligned data across all entities. By managing everything in one place, you'll also make change management much simpler.
2. Plus, with our group-level ERP integrations, you can integrate your ERP for all your entities at the same time. This seamless integration means your master data syncs automatically between the two systems, making it easier than ever for your team to process expenses quickly and breeze through the month-end.
3. Next, apply your customisation as above.

How to set up custom expense fields and categories in Payhawk

At Payhawk, our platform offers a list of built-in expense fields, including category, document date, document type, supplier, and team. You can also create unlimited custom fields for deeper levels of analysis and reporting. You can also assign visibility settings and add requirements to mandate field filling upon submission or review.

Creating custom expense fields in Payhawk is quick and straightforward; here's how it looks for our customers:

• Log in to the Payhawk portal
• Go to Settings > Expense fields > Custom fields
• Click on "+ Add custom field" to create a new field
• Define the label, external ID, and managers for the custom field
• Set visibility, submission requirements, and automatic population options as needed

Creating custom categories is just as straightforward:

• Go to Settings > Expense fields > Built-in fields > Categories
• Click on "+ Add category"
• Enter the name of the new category and its account code
• Optionally, add a default tax rate (you need to create a tax rate expense field first)
• Click "Save"

There are plenty of other options for customisation, including choosing category managers for custom approval flows and creating supplier-specific categories. So, for any category you create and assign to a particular supplier, any expenses matched to that supplier will automatically have these values applied.

Learn more about our custom expense fields in this story from global events company, GDS Group or request a personalised demo to see them in action.