I worked it out...

1. Create temporary table

2. Bulk insert to temp table from file

3. Change FK values

4. Insert contents of temp table into real table

5. Drop temp table

Seems to work...

Nice one bro. That worked a treat!

I understand about the 150 values but why is the length of the int not...

Cheers Andy, that did the trick. Here is the command string I ended up using...

bcp {dbname}.dbo.tblUsers out c:\data.csv -S{Server/instance} -U{uname} -P{pword} -w -t,...