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A small master data error can create a surprisingly big problem, and the cost isn’t always where you’d expect.
When we talk about poor-quality master data, the conversation often centres on getting the right information in the system. Are the customer details correct? Is the VAT registration number valid? Is the address complete? Have all the necessary fields been filled in?
These are all important questions, but there’s another one worth asking: what happens when that information is wrong in the first place?
Because correcting a mistake in master data isn’t always as simple as changing a field and moving on. Depending on when the error is discovered, it can mean correcting tax that has already been calculated, reversing transactions, issuing credit notes and reissuing invoices. It can also mean updating reporting systems, repeating approval processes and explaining to customers why they’ve received a corrected invoice.
Suddenly, what started as an incorrect VAT number or address has become a much bigger job.
And for tax teams, these are often the kinds of tasks that quietly eat into the working week. They might be logged as invoice queries, reporting issues or general administrative work, without anyone joining the dots back to the original master data error.
The real cost isn’t just fixing the data. It’s everything that happens because the data was wrong.
Imagine a customer is onboarded with an incorrect VAT registration number. Perhaps the information provided wasn’t complete, or the details weren’t properly checked before being added to the ERPEnterprise resource planning (ERP) is a type of software that organisations use to manage main business processes.. The error might not be obvious at first, and transactions continue to be processed using the information available.
Then an invoice is rejected, a customer queries the tax charged, or a discrepancy comes to light during a review.
Now someone needs to investigate what went wrong. The master data needs correcting, but that might only be the beginning. Depending on the circumstances, the original transaction may need to be reversed, a credit note issued and a replacement invoice sent. The corrected information may also need to be reflected across the ERP and reporting systems, with approvals repeated where necessary.
If the original invoice has already reached the customer, there’s another layer to consider. Has it been processed? Has it been paid? Does the customer need to update their own records? Has the error affected other transactions?
What looked like a small data issue can quickly turn into a chain of work involving several people and systems, and that’s just one transaction.
Now imagine the same incorrect information has been replicated across hundreds or thousands of invoices before anyone spots it. The original mistake might have been made once, but the work required to put it right multiplies with every affected transaction.
In a recent webinar, Andrew Bohnet shared an example of a US-based business that identified around 2,000 invoices with incorrect tax during a review of historical data from the previous year. Each affected invoice had the potential to create further work, including corrections and credit notes.
It’s a useful reminder that data errors don’t always stay where they start. One incorrect record can have consequences far beyond the original entry.
Of course, the time involved will vary depending on the business, the systems it uses and the nature of the error. But even if correcting an individual transaction takes only 30–90 minutes, the effort adds up quickly when multiple invoices are affected. Add in investigation, approvals and communication with customers, and the total can be considerably higher.
Then there are the costs that are less obvious.
Every correction takes time away from other work. Tax professionals may find themselves investigating discrepancies, checking transactions and chasing updated information instead of focusing on tax planning, improving processes or supporting wider business decisions.
Repeated errors can also undermine confidence in the data itself. If reports regularly contain discrepancies, teams may start double-checking the figures rather than relying on them. Additional manual controls creep in, spreadsheets appear to fill gaps, and processes that were supposed to save time become another thing to maintain.
Before long, the business isn’t just paying for the original mistake. It’s paying for the effort needed to work around it, too.
There’s also a risk that errors go unnoticed until much later. As tax authorities increasingly use digital reporting and transaction-level data to identify discrepancies, inaccurate information can be harder to overlook. Depending on the circumstances, incorrect tax treatment or delayed corrections may create compliance issues or potential penalties.
So, how do you avoid getting caught in this cycle?
The obvious starting point is to get the data right before it enters the system. That means having a clear onboarding process, asking customers and suppliers for the information you actually need, and checking that what they provide is complete and accurate. It also means making validation part of the process, rather than relying on someone to spot a problem further down the line.
But getting the initial entry right isn’t the whole answer. Master data changes, businesses evolve and information can become outdated. That’s why ongoing validation and maintenance matter just as much as the initial check.
Tools such as LimeLyte® Entity Manager (LLEM) can help tax teams validate VAT registration numbers, identify errors and discrepancies, and maintain better-quality information over time. By making potential issues more visible, teams can investigate and address them before they continue to affect transactions and create further work.
The aim isn’t simply to have a clean database. It’s to reduce the amount of rework that poor-quality data creates across the business.
Because every corrected invoice, repeated approval and manual investigation has a cost, even if that cost never appears under a line item labelled master data errors.
The question is: how much time is your team spending correcting problems that could have been prevented at the point of entry?
Getting master data right might not always feel like the most urgent priority. But when the alternative is repeatedly fixing the same problems downstream, it’s worth looking at what those errors are really costing you.
If you’d like to see how LLEM can help your team validate, monitor and maintain VAT registration data across your global operations, you can book a demo here.
