When should I use Excel or CSV upload?
Use Excel or CSV upload to load actuals from your ERP into Finstack when there's no direct ERP connector available. The file becomes a data source under Setup → Sources, the same way a direct ERP connection would.
This article does NOT cover:
Uploading forecast scenarios → see Forecast
Fetching Finstack data directly inside Excel with our Office Add-in → see Excel sheet integration
Excel or CSV — which should I choose?
Both are static-file uploads into Sources. The difference is the granularity of the data, which determines whether drill-down works in Reporting.
Excel upload
Level of detail: trial-balance — per General Ledger Account (GLA), per month.
Drill-down in Reporting: not supported (values are roll-ups).
Effort to produce from your ERP: low — almost all ERPs can export a trial balance.
Multiple entities in one file: yes (one tab per entity).
Adding new months: re-upload the full history each time.
CSV upload
Level of detail: transaction-level — individual entries with fields like date, supplier, etc.
Drill-down in Reporting: supported.
Effort to produce from your ERP: higher — requires a transaction export in a supported CSV format.
Multiple entities in one file: one entity per file.
Adding new months: upload the full history, or only new months side-by-side. Max 20MB per file.
Choose Excel for the lightest setup. Choose CSV if you need drill-down to individual transactions in Reporting.
How do I upload an Excel file (trial balance)?
Go to Setup → Sources and click + Add source (top right)
Select Excel file
Download the template via "Need a template?"
In the template, fill in the top-left fields:
Entity name — used for reporting
Currency — e.g., EUR, USD
First reporting month — to set an opening balance for the Balance Sheet, use the month before actuals start (e.g., Dec-25 if actuals start Jan-26)
Enter values, observing these conventions:
P&L signs: negative for income, positive for costs
BS signs: negative for liabilities, positive for assets
BS values must be mutations (not closing balances)
The sheet must sum to zero. Use the Check row at the top to verify. Ensure the result is processed, i.e. current-year earnings need to be posted to the BS
Use the end-of-year column (e.g., Eoy-25) to clear P&L rows:
post "-SUM(row)" to empty the GLA, then post "SUM(end-year column)" to the BS GLA used for last year's result
Multiple entities in one file: add a new tab per entity, each with its own entity name and currency in the top-left
Press Confirm to upload.
If the upload fails, the warning message indicates the issue. For help, use the in-app chat.
How do I add new months to an Excel upload?
Excel uploads expect the full history every time. To add a new month, re-upload a complete file via Upload new file (on the right).
How do I remove an Excel upload?
Click the garbage-bin icon on the right. This removes all data from the upload, including its mapping.
How do I upload a CSV file (transaction level)?
CSV files are transaction-level, so drill-downs in Reporting are available. Unlike Excel, CSV files can be uploaded side-by-side — you don't re-upload history each month, you add new files. Max 20MB per file.
Go to Setup → Sources and click + Add source (top right).
Select CSV file.
Provide
Entity name — used for reporting.
Currency — e.g., EUR, USD.
CSV format — pick from supported formats. To request a new format, use the in-app chat.
Click Upload CSV file and select the file.
Confirm. Finstack will process the file. Errors usually indicate a format mismatch.
To add files for new periods: click Upload new file, then Add file on the right.
⚠️ Avoid overlapping periods between files — duplicate values will appear in reports.
How do I add new periods to a CSV upload?
Use Upload new file to see all earlier files, then either:
Add file — append a new file alongside existing ones (typical for new months).
Upload new version — replace all previously uploaded data.
How do I remove a CSV upload?
Use the garbage-bin icon on the right to remove the full set, or open Upload new file to delete individual files.
What are the next steps after uploading?
Configure Your Structure
Go to Setup > Structure to organise your P&L, Balance Sheet, and Cash Flow statements. See Structure Help Page.
Map Your Data
Go to Setup > Mapping to assign each GLA to the correct line in your structure. See Mapping Help Page.
Once mapping is complete, the uploaded data flows into your reports.