CSV and JSON Import Errors

How to fix common CSV and JSON import errors in Forbidden Finance, including date format issues, missing columns, amount parsing, and supported file formats.

Overview

Forbidden Finance lets you import transactions from CSV and JSON files exported from other apps or your bank. Most import errors come down to date format mismatches, missing required columns, or unexpected amount formatting. This guide covers the most common errors and how to fix them so your import goes through cleanly.

Forbidden Finance supports direct imports from YNAB, Mint, Monarch, and generic CSV or JSON files. Each format has slightly different column expectations, which are outlined below.

Supported Import Formats

Source	How to Access
YNAB	Export from YNAB and import using the YNAB format option
Mint	Download your Mint CSV export and import using the Mint format option
Monarch	Export from Monarch Money and import using the Monarch format option
Generic CSV	Any CSV file with the required columns (Date, Amount, and Description/Merchant)

When you start an import, Forbidden Finance asks you to select the source format. Choosing the correct format ensures the column mapping is handled automatically.

Common Errors and Fixes

Wrong Date Format

Error message: "Unable to parse date" or "Invalid date format"

Your CSV uses a date format that does not match what Forbidden Finance expects. Common mismatches:

Your CSV Has	Expected Format
`04/11/2026`	`MM/DD/YYYY`
`11-04-2026`	`DD-MM-YYYY` (sometimes confused with MM-DD)
`2026-04-11`	`YYYY-MM-DD`
`April 11, 2026`	Written-out dates are not supported

How to fix it:

During the import preview, check the date format dropdown and select the format that matches your CSV.
If your dates use a written-out format (like "April 11, 2026"), open the CSV in a spreadsheet app, reformat the date column to MM/DD/YYYY or YYYY-MM-DD, and re-export.

Missing Required Columns

Error message: "Required column not found" or "Missing column: [column name]"

Your CSV is missing one or more required columns. The minimum required columns depend on the format:

Format	Required Columns
Generic CSV	Date, Amount, Description (or Merchant)
YNAB	Date, Payee, Category, Memo, Outflow, Inflow
Mint	Date, Description, Amount, Category
Monarch	Date, Merchant, Amount, Category

How to fix it:

Open the CSV in a spreadsheet app and add the missing column.
If the data exists but the column header is named differently (for example, "Vendor" instead of "Merchant"), use the column mapping screen during import to manually map your columns.

Amount Parsing Errors

Error message: "Unable to parse amount" or "Invalid amount"

The amount column contains values that cannot be interpreted as numbers. Common causes:

Currency symbols: $50.00 instead of 50.00. Remove currency symbols before importing, or the importer strips them automatically if they are standard ($, EUR, etc.).
Thousands separators: 1,250.00 is usually handled, but 1.250,00 (European format) may cause issues. Use a period as the decimal separator.
Parentheses for negatives: (50.00) instead of -50.00. Replace parentheses with a minus sign.
Non-numeric characters: Text like "N/A" or "Pending" in the amount column causes parsing failures. Remove these rows before importing.

How to fix it:

Open the CSV in a spreadsheet app and clean the amount column so every value is a plain number (e.g., 50.00 or -50.00).
Remove any rows with non-numeric amounts.

Duplicate Transactions After Import

If you import the same CSV file twice, Forbidden Finance may create duplicate transactions.

How to fix it:

Before importing, check if you have already imported this file. The import screen shows a history of recent imports.
If duplicates were created, you can select multiple transactions in the transaction list and delete them in bulk.

File Too Large or Times Out

If your CSV is very large (thousands of rows), the import may take longer or time out.

How to fix it:

Split the CSV into smaller files (500-1000 rows each) and import them separately.
Remove unnecessary columns before importing to reduce file size.

Tips

Before importing, open the CSV in a spreadsheet app and scan the first few rows. Confirm that dates, amounts, and descriptions look correct. Catching formatting issues before you start saves time.

Use the import preview screen to verify column mapping before committing. Forbidden Finance shows you the first several rows as they will be imported, so you can spot problems early.

If you are migrating from YNAB, Mint, or Monarch, select the specific format during import instead of "Generic CSV." The purpose-built importers handle column names and formatting automatically.

CSV and JSON imports create manual transactions. If you later connect the same bank account, you may see duplicates between imported and synced transactions. Review and delete duplicates as needed.