We acquired a company and now we run two systems

An acquisition gets described as a growth event, and it is. But for the finance team it is also an operations event, and the work does not begin on the day the deal closes. It begins at the first month end after, when someone has to produce one set of numbers for a business that is now running on two systems.

Most groups plan the deal carefully and plan the reporting afterward. The result is a period, often much longer than anyone expected, where the business is bigger but the numbers are slower and less trusted than they were before. This is what actually happens in that period, why it drags on, and how to tell whether you have an integration problem or a consolidation problem, because the fix is different.

The month after the deal is when you find out

On paper, consolidating two companies sounds like addition. In practice the two businesses almost never share a chart of accounts, a fiscal calendar, a revenue recognition policy, or a definition of what counts as a department. So before anything can be added together, it has to be mapped, and the mapping usually lives in one person's head and one spreadsheet.

That first close is the moment the real scope becomes visible. Accounts that looked equivalent turn out to be defined differently. The acquired company books an expense in a category your team does not use. Intercompany transactions that did not exist last quarter now have to be identified and removed. None of this is difficult work. It is just manual, repetitive, and it happens again every single month.

Integration and consolidation are not the same problem

These two get used interchangeably and they should not be, because they have different answers.

Integration is about operations: whether both businesses eventually run on the same system, share a chart of accounts, and follow the same processes. It is expensive, disruptive, and sometimes genuinely not worth doing. A manufacturer that acquires a services firm may have good reasons to leave the two operating separately for years.

Consolidation is about reporting: whether you can produce one accurate, timely, defensible set of numbers for the whole group. This is not optional, and it does not get easier by waiting.

Conflating the two is what causes groups to stall. The integration question feels enormous, so the decision gets deferred, and while it is deferred the consolidation work continues to be done by hand every month. You can decide to leave the systems separate and still fix consolidation. Those are independent choices.

What running two systems actually costs

The cost is rarely a line item, which is why it goes unmanaged. It shows up in five fairly predictable places.

1. The close stretches and stays stretched Each entity closes on its own timeline, then someone exports both, maps the accounts, eliminates intercompany activity, and rebuilds the group picture. A close that took a week before the acquisition commonly runs three weeks after, and the extra two weeks do not shrink on their own because nothing about the process changed.
2. Intercompany activity becomes manual reconciliation The moment the two entities transact with each other, someone has to find both sides of every transaction and remove them so revenue and expense are not double counted. In a single system this is a routine elimination. Across two systems it is a monthly hunt, and anything missed inflates the group numbers in a way that is genuinely hard to spot later.
3. Leadership stops trusting the numbers When two entities define revenue, headcount, or margin slightly differently, the consolidated report becomes debatable. Meetings start with a discussion about whose number is right rather than what to do about it. That erosion of trust costs more than the finance hours do, because it slows down every decision that depends on the reporting.
4. Currency and calendars quietly diverge If the acquisition crossed a border, someone is now choosing exchange rates and applying them consistently every period, by hand. If the two entities have different fiscal calendars or close cadences, the group report is comparing periods that are not quite the same. Both problems are manageable and both are invisible until an auditor asks how the rate was determined.
5. The data gets worse while you wait Every month on a manual process adds another set of adjusting entries, another spreadsheet version, and another undocumented mapping decision. If the group eventually does consolidate onto one system, it will be migrating that accumulated mess rather than clean records. Waiting does not preserve the option. It makes exercising the option more expensive.

The spreadsheet consolidation trap

Nearly every group starts by consolidating in a spreadsheet, and that is a reasonable first move. It is fast, it is free, and for two entities in one currency it genuinely works.

The trap is that it keeps working just well enough. It does not fail loudly at three entities or at the first foreign subsidiary. It degrades: a little slower each month, a little harder to explain, a little more dependent on the one person who built it. Groups often do not recognize the problem until an audit asks how a figure was derived, or until that person is on vacation during close.

The issue is not accuracy. A careful person can produce correct numbers in Excel. The issue is that a spreadsheet consolidation has no audit trail, no enforced account mapping, no version control, and no way for anyone else to verify the result without rebuilding it. Those are the exact properties an auditor, a lender, or an investor will ask about.

A self-check before your next close

Run this before the next month end. It takes a few minutes and tells you whether you are in a transition period or a permanent state.

• Has our close taken longer than it did pre-acquisition for three or more consecutive months?
• Does producing the group numbers require exporting from more than one system into a spreadsheet?
• Is there exactly one person who knows how the consolidation mapping works?
• Do intercompany transactions get identified and eliminated manually each period?
• If an auditor asked how a consolidated figure was derived, could we show the trail without rebuilding it?

If you answered yes to the first four or no to the last one, the consolidation process is not a temporary bridge. It is now how your group reports, and it will keep costing what it costs until something structural changes.

That does not mean you need to merge both businesses onto one system. It does mean the consolidation question deserves its own decision, separate from the much larger integration question, and sooner rather than after the next acquisition.