The Mapping step is central to the Flatfile import flow, confirming the alignment of columns from your source file with the fields in the destination format. Any data in columns mapped at this step will be migrated into the Review table.

Mapping is also where Flatfile brings the most magic. Using mapping choices recorded from 1.8 billion (and counting!) rows processed in Flatfile, we’ve trained a machine learning model that works alongside memory of your and your colleagues’ past selections to accurately predict over 90% of matching actions. When available, these mappings will be applied at the mapping step, reducing the number of mapping actions we ask you to make.

When starting the mapping process, if you're uploading a file with multiple sheets, you will see a screen that will allow you to choose which of the sheets to map to the destination sheet. If you are initializing the import from a "Files" tab, you'll also be able to choose which sheet to import data to. If you are importing directly to a sheet, this will be auto-selected for you.

Once the relevant information here has been selected, you'll be brought to our Map Fields page. You should see most or all of your incoming fields automatically mapped to a destination field.

💡Pro Tip

Think we got it wrong? Use the round arrow in the top right corner to clear all mapping suggestions automatically.

When we need input, the corresponding field in the destination fields will remain blank. Use the dropdown to select the relevant field from the destination field list. To help you map those fields, you can hover over the field titles and see a brief data preview for that specific field on the right. If you hover over the destination field titles, a description tooltip will appear if that field has a description.

You may have an option in the list of destination fields to "Add as New Field". If you have this option and use it, a new column will be added to the review table with this incoming column and its data.

Once you’ve finished mapping all the necessary fields, click the Continue button in the top right corner.

⚠️ Any source fields that are not mapped to a destination field will be excluded from the import.

If there’s an option/category destination field, you will be taken to a separate mapping screen to map the individual values for that option field. If there are any values that are not automatically mapped, you'll be able to access a menu with all available options, like on the previous page. If present you can select the correct option here.

If the correct value is not present, you have two additional options to choose from: "Keep this value as is" or "Do not import". "Keep this value as is" will import that value into the option field wherever it is listed in your file. Please note that if it is not one of the pre-defined values in the option field, it will display with an error in the review table. "Do not import" will keep that one value from being imported (not the whole column!) and instead will display a blank space in the corresponding cell in the review table.

⚠️ If you are choosing what to do with "Cells with no data", the option "Keep this value as is" will be grayed out, as it is functionally the same as "Do not import". "Do not import" will display a blank space in the corresponding cell in the review table.

Once you're happy with your selections here, Click "Continue" at the top right and you'll be brought to the review table. You should see the data from your file appear in the table in the columns you've selected.