Beyond Excel: Using simple API’s to enhance compliance and reporting
- Mark Hart
- Mar 4
- 5 min read
If you’ve worked through a tax compliance, tax provision or financial statement reporting cycle, you’ll recognise this pattern: you’ve got the numbers. Everything ties out. The standard reports are produced. They make logical sense.
Then comes the next question(s) - usually from Group Finance, Audit, or the CFO: “Can we see how it compares to the prior year… by entity… and do some trend analysis?” or “Can we run a report that checks intercompany adjustments and balances tie out?” or [fill in the blank]?
With dedicated systems, the answer is often yes: simply run the relevant report. But standard reports will only go so far, and so the answer is then too often: “Give us a day… we’ll build it in Excel.”
Excel is brilliant. It’s also not a reporting platform, an integration layer, and a governed transformation engine yet many tax teams end up using it as all three. This article is about a practical alternative: using APIs and lightweight data workflows to enhance reporting and build tax team managed integrations.
“Out-of-the-box” reports are brilliant… but sometimes you need to go further
Many solutions do a solid job producing standard reporting. But tax teams typically hit limitations when they need more than the standard:
the format doesn’t match internal reporting requirements
it’s hard to see the “why” behind a number without manual analysis
prior-year or version comparatives aren’t readily available
repeating the same custom views every cycle starts to be a regular spreadsheet exercise
So the question becomes: how do we move from standard reports → readily available additional insight, reliably, every time?
Why Excel keeps winning (until it starts costing you)
Excel wins because it’s flexible, familiar, and fast to prototype. But it starts to creak with complicated, often interdependent, workbooks leading to:
multiple manual extracts from your tax/reporting solution, with required re-formatting
fragile mapping logic
scaling problems as complexity grows (more entities, more iterations, more questions)
key person dependency where complex workbooks are managed and maintained by a key team member
The shift: build a clean path from source → custom rules → insight
The aim isn’t to rip out Excel - it’s to stop relying on Excel as the engine. A modern approach usually has two or three building blocks:
APIs (to pull/push data consistently)
ETL / workflow tools (to apply rules, mapping, validation, and repeatability)
Dashboards / custom outputs (optional - if tables aren’t enough)
The point isn’t to custom-build software. It’s to use low-code workflows with clear rules, controls and ownership that sit with the tax team.
APIs in plain English (and why tax should care)
You’re probably already using APIs every day as Google maps, payments, notifications are all API-driven. For anyone who wants a simple grounding, we’ve written an introduction called Understanding APIs: Unlocking the Power Behind Modern Tax Technology.
But the key for tax and finance is simple: set them up once and let them run in the background. Combined with a true ETL tool, this can turn hours/days into minutes. In practice, APIs turn “export from” systems into systems you can “connect to”.
That unlocks something powerful:
consistent data pulls (same query, same result, every time)
controlled data pushes (with validation and logging)
the ability to integrate your source systems, your tax system, and your statutory reporting tools in a governed way, on your terms
And that’s where insight starts to scale.
Using APIs in Excel
A very sensible question is: can I use APIs to extract and submit my data directly from Excel? The answer is certainly yes, but the challenge is the flow. Here’s a typical pattern for pulling a dataset:
authentication token (your permission slip)
dataset required (the universal ID such as 1575da8a-69a2-43a8-a8a3-b33200dd3209, sadly not 2025 trading entities)
list of entities/units required (the universal IDs - again, not the name)
pull report/category file based on the above
repeat
Note also the output is JSON, not human. So each step needs unpacking and repacking.
Possible in Excel? Yes. Practical in Excel? In our view, no. This is why people resort to VBA (Excel coding), slowly turning your tax team into an IT department or removing their independence to maintain their own process. This is also why our favorite tool for working with APIs is Alteryx (I’ve written more on this in How Alteryx is transforming tax processes (and how your team could benefit).
Three practical use cases we’ve seen recently
1. Trial balance loading
Most dedicated systems start with an account balance load, often with a set format. Anyone who’s done this knows the pain:
source and destination entity codes differ
chart of accounts updates
reclass or aggregation logic
improper formatting
late TB iterations
entities loaded individually requiring 100s of separate imports
One ETL workflow can take the repeatable parts of this (mapping, validation, formatting, bridge creation and load) and make them:
automated (including upload via API)
documented
consistent
The real benefit isn’t just the huge time savings. It's that multiple TB iterations and last minute adjustments become manageable, and the team can manage by exception rather than reworking the same transformation steps every time. A big win for the team.
2. Trend and comparative analysis: analyse and explain the numbers faster
One of the most valuable upgrades teams can make is trend and variance analysis. Instead of treating the calculation/computation like a static output you review once, you can:
pull computation results across periods/entities via API
compare drivers of movements (rates, adjustments, elections, permanent/temporary impacts)
surface exceptions automatically (outliers, missing inputs)
create views that answer the “why” without building workbooks
utilise prior-year data to support meaningful estimated provisions
This is where tax teams move from producing results to explaining results - quickly and confidently.
GAAP adjustments in statutory reporting: manage cumulative adjustments with control
Statutory reporting often involves recurring adjustments, especially when managing multiple GAAPs:
recurring GAAP differences
local statutory adjustments
cumulative roll-forwards and reversals
A well-designed workflow can maintain an adjustment record with:
clear categorisation
automatic cumulative roll-forward logic
automated submission of resulting journals via API
This is where “automation” becomes governance: fewer surprises, cleaner audit conversations, and much less manual reconciliation.
The bigger win: integrations on your terms
Once you can connect systems reliably, you’re no longer boxed into a single workflow methodology. Use an ETL tool and APIs to dictate how data flows between:
ERP / finance source systems
your tax solutions
statutory reporting tools
BI layers / dashboards
That means tax can design the process around business needs, not your licensed software.
How to avoid boiling the ocean (or becoming an extension of IT)
If you’re a tax or finance leader deciding where to start, begin with one question: what’s the most painful repeatable task we do every cycle? Pick one. Then build a small, governed proof of value: defined inputs, defined outputs, defined rules, validation steps, clear audit trail.
Keep it maintainable: minimal custom code, documented logic, and a process the tax team can run and troubleshoot. And if you need some help getting started, reach out, in many cases we have pre-built elements ready to be leveraged.
If you could automate one recurring Excel report from your tax world tomorrow… which would it be? 👇
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