Best practices

Let's begin by reviewing some best practices that will save you a lot of time and frustration when performing your imports.

Internal IDs

My first recommendation may sound inane and irrelevant; however, I suggest the first thing you do is go to Home icon | Set Preferences and check the SHOW INTERNAL IDS checkbox:

Set Preferences

The easiest way to add or update data is to use the internal ID for a record. Incidentally, you can see the internal ID of each record by looking at the URL of that record. It is easier to reference the ID than it is to reference the name of the record because you can't make spelling mistakes when referencing an ID. A name, on the other hand, can be misspelled or contain slight changes that will result in an import error, such as an extra space in the field:

Transaction internal ID

Don't worry, you don't need to identify internal IDs manually using their URLs as long as you turn on the SHOW INTERNAL IDS checkbox. Now each record's internal ID will appear...