It depends on the platform you pick on the Import page:

- MetaTrader 4, MetaTrader 5 and Match Trader: .htm or .html, up to 5MB

- cTrader: .csv or .txt, up to 10MB

- Trade Nation: .csv, up to 10MB

- Other Platform: .csv or .txt up to 10MB, .htm or .html up to 5MB

Spreadsheet workbooks can't be imported - .xlsx, .xls, .xlsm and .xlsb - and we go by what's inside the file, so renaming one to .csv won't get it through. Open it in Excel, use File > Save As to save it as CSV, and upload that instead. PDF statements aren't supported either.

If a file is too big, export a shorter date range and upload it in a couple of goes.