Because Excel lets you enter anything in any cell, there are as many spreadsheet formats as there are spreadsheet creators. While your spreadsheet may make sense to you, a standard database program might have more trouble understanding your intentions. If your spreadsheet is arranged in a way that doesn't fit the model of a traditional database table (which you'll be able to identify in a minute), you need to tweak the format of your Excel data before you import it into QuickBase.
QuickBase needs your spreadsheet to be organized in consistent rows and columns. Use the following guidelines to organize your spreadsheet before importing it into QuickBase:
Each of your rows should represent one record. Rows become individual records in QuickBase. All rows should look similar.
Cells in each column should contain the same kind of information. Each column becomes a field and the cells in a column become values for that field in QuickBase.
Your spreadsheet should not contain a title in the row, as shown in the example below. If it does have a title, delete it. If the first row is missing data from one or more of the right-most cells, QuickBase does not import any data from those final columns, even if there is data in other cells in those columns. That means that in the example below, only columns A and B would be imported.
Each cell should have a label in the first row of data indicating the kind of information it holds. You can set these labels as field names in QuickBase.
Blank rows are not imported. You can either delete them or ignore them in Excel.
Your spreadsheet should not have empty columns that appear to the left of your first column of data; they are imported as blank values into QuickBase. You can delete them before import, or you can select Do Not Import for those columns when previewing the import in QuickBase.
Excel formulas are not imported; QuickBase imports only the value in an Excel formula cell. Before importing, correct any Excel formula cells that say "#ERROR". Excel formulas that refer to values in a different row are not replicated by a QuickBase formula-type field. QuickBase has its own formula language that you can use to perform the same kinds of calculations your spreadsheet performs.
Ensure text notes and currencies are handled correctly during import. See other format issues, below.
QuickBase imports only the first worksheet in an Excel file. If you need to import an additional worksheet from an Excel file, move that worksheet so that it is the first sheet in the workbook, save your changes, and then import the .xlsx file.
Before you begin cleaning up your Excel spreadsheet for import, it might look something like the one in below. This is a list of equipment sales. Most rows in this spreadsheet represent sales.

This spreadsheet is a good start, but it's
not ready for import into QuickBase. The data is not consistent. For example,
the title in row 1 is not a record of a sale and does not contain data
in each of the columns that you want to import, so delete it. Also, QuickBase
won't know who sold the color printer in row 5. QuickBase reads
each row as an individual record and can't infer values based on indentation.
If you import that line as is, the sale won't be connected with a rep.

Since you only want to import sales records, delete the title in row one. Then connect each sale with a sales rep by filling in the blank cells, highlighted in yellow. Leave the row of column headings. QuickBase will use it to name your columns. Don't worry about entire rows that are blank. QuickBase ignores them.
Note: If your spreadsheet contains a column or row that totals, delete it. QuickBase will total for you automatically. Excel formulas don't carry over into QuickBase. The import will think your Totals column is another column of data you entered manually, which may confuse you later when it does not update automatically.

Following the changes, this spreadsheet now flows seamlessly into QuickBase. Each sale is connected with a Sales Rep and there's no extraneous non-sale related data.
Does one cell in your spreadsheet contain a list of items? For example, do you list several contacts belonging to one company in a single cell? Or do you type keep a "notes" type column to remind you of upcoming dates?

Excel cells that list multiple items don't usually fit well into QuickBase.
If these are truly just text notes, that's fine. You can import the column into a Text - multi-line field type. But if a single field lists discrete pieces of information that you want to track individually (like dates and names), this kind of freestyle data entry won't import cleanly into QuickBase. You can import this data into a text field in order to get it into QuickBase, but it's likely that this data should be split up. In the case of a deadlines list like the one pictured here, each event should probably become an individual activity record or perhaps its own date field. Unfortunately, there's no magic wand that will split them up. You must do this manually. You can turn them into individual rows or columns here in Excel, or import the column into a QuickBase text field along with your other information and manually create additional records or fields later in QuickBase. Either way, the process is cumbersome. However, work you do now will pay off later in the form of an application that's well-designed and easy to use.
If your spreadsheet contains US currency (dollars), QuickBase correctly sets the field type to Currency. However, if your spreadsheet contains non-US currency, QuickBase sets the field type to Numeric. You can change the field type to Currency when previewing the import. Choose the appropriate symbol on the field properties page for that field.