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
Trial balance or transaction upload — 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.
Trial balance upload (Excel — Trial balance)
Level of detail: 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.
Transaction upload (Excel — Transactions, or CSV — Transactions)
Level of detail: transaction-level — individual entries with fields like date, supplier, cost center, etc.
Drill-down in Reporting: supported.
Excel: multiple entities in one file (one tab per entity), max 90,000 rows per file. Each tab must contain the entity's full transaction history.
CSV: one entity per file, max 20MB per file. Add new months side-by-side — no need to re-upload history.
Choose the trial balance upload for the lightest setup. Choose a transaction upload 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 with the Trial balance label
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 transactions via Excel?
The Excel transaction upload uses a general template — max 90,000 rows per file. You can include multiple entities in one file (one tab per entity); each tab must contain the full transaction history of that entity.
Go to Setup → Sources, click + Add source (top right), and select Excel with the Transactions label.
Download the template.
Fill in the top-left fields per tab: Entity name and Currency. Only fill the cells with a grey background.
Enter the transactions, one row per entry, with the columns:
PL / BS — whether the account is a P&L or Balance Sheet account
Account nr and Account description
Entry Date, Entry number, and Description
Amount — debit values as positive, credit values as negative numbers
Optional: Cost center, Relation name, and Relation type (e.g., Customer or Supplier)
Use the Check cell at the top to verify the file: it confirms that the result from the Balance Sheet matches the result from the P&L ("All set"). A mismatch must be resolved before uploading.
Upload the file and confirm.
To add new months, re-upload a complete file — each tab must always contain the entity's full history. Side-by-side files per period apply to CSV uploads only (see below).
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 with the Transactions label.
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.
⚠️ Files with overlapping periods trigger an error notification — the upload is blocked until the overlap is resolved.
How do I manage the uploaded files of a source?
Go to Setup → Sources and click Upload new file on the relevant entity. The Uploaded files overview opens: these files together make up the transaction data for this source, with the date range, upload date, and uploader per file.
Add a period: click Add file and upload the file for the new period.
Transactions in a period changed in your ERP: delete the existing file for that period (bin icon) and add the new file.
Download a file: use the download icon.
⚠️ Avoid overlapping periods between files — this will trigger an error notification and prevent you from uploading the new file.
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.
Can I manage a separate entity via transaction uploads (e.g., for IFRS adjustments)?
Yes. An entity created via transaction upload is treated as a full entity in Finstack: its data can be eliminated via the intercompany elimination methods, and shown or hidden separately via the entity filters in Reporting.
This makes transaction uploads useful beyond loading ERP data — for example to manage a dedicated entity for IFRS adjustment bookings alongside your regular entities.
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.