Why split a CSV before importing it?
Spreadsheets and bank portals happily export years of history in one file. Accounting software is less forgiving. QuickBooks Online stops at 350 KB per upload, which is roughly 3,000 to 5,000 transactions depending on how long the descriptions are. Other systems cap the number of rows, time out on large files, or simply become hard to review when you're staring at ten thousand lines in a single import screen.
Splitting the file first keeps each import small enough to check properly. If something goes wrong with one part, such as a column mapped to the wrong field, you only undo a few weeks of transactions instead of a whole year.
How to import the split files into QuickBooks Online
- In QuickBooks Online, open Transactions and choose Bank transactions.
- Open the Link account menu and select Upload from file.
- Drag in the first part, for example
statement-part-01-of-04.csv, then choose the QuickBooks account it belongs to. - Map the columns. QuickBooks accepts either a 3-column layout (Date, Description, Amount) or a 4-column layout (Date, Description, Credit, Debit), and asks for the date format used in the file.
- Review and confirm the transactions, then repeat with the next part. Use the same mapping each time; because every part has the same header, QuickBooks will usually remember it.
Import the parts in order. It isn't strictly required, but working from oldest to newest makes it much easier to match deposits to invoices and spot gaps.
Choosing between size and row count
Split by size when the destination enforces a file size limit. The splitter adds rows to a part until the next one would push it over the limit, counting the repeated header and line endings, so the result is exact rather than an estimate. Stay at 350 KB for QuickBooks Online; there is no benefit to going much lower.
Split by rows when you need predictable chunks, for example to hand off 500 transactions at a time to different people for categorization, or when an import tool documents a maximum number of records.
Tips for clean results
- Don't open and re-save the CSV in Excel first. Excel can silently change dates, drop leading zeros from check numbers and turn long reference numbers into scientific notation. Split the original export instead.
- Remove summary rows. Some banks add totals or "ending balance" lines at the bottom. They will end up in the last part and QuickBooks may reject them. Delete them from the original first, or skip them in the import screen.
- Keep the parts together. The ZIP download names each file with its position (
part-02-of-05), so the order is never ambiguous. - Got a QBO or OFX file that's too big? Those can't be cut like a CSV because each part needs its own header and balance. The statement converter splits them by date range automatically.
Supported files
Comma, semicolon, tab and pipe separated files are detected automatically, with UTF-8, UTF-16 and Windows-1252 encodings. Files with or without a header row both work. Line endings from Windows, macOS and Linux are preserved as they are in the original.