An external key is an id or key value that is already assigned to your constituents e.g. from an existing database you have.

If can be useful to bring in the external key when you import constituents into Donorfy as you can then use the external key when you need to import timeline entries.

This is what you should do

• When you import your constituents make sure you complete the column ‘ExternalKey’ in the data preparation template worksheet you are using - an external key can include letters and numbers and be up to 50 characters long.
• When you import timeline entries put the correct value into the ExternalKey column in the data preparation template worksheet you are using

If you will be importing from a number of different systems it makes sense to prefix the external keys with the name of the system to make them unique, e.g. AccessDB_0001

If you haven't got an external key available you can still match timeline entries to constituents by other means - see the knowledgebase article about importing timeline entries for help with this