Thanks p45cal.

I've managed to identify the errant cells by clearing formatting

The download is from Portugal and is being used in Dublin, so both in ddmmyyyy format

I've never used PowerQuery, but would be keen to work with you to automate it if that's ok.

I do the editing directly in the .csv file. The only amendments I make are to remove cell merging (in several rows) where this exists and also I may delete some rows before running the "Replace" activity and then copy/paste to master sheet in .xlsx

Appreciate the offer to work with you further in DM. I will send to you now.

Thanks for the support.

Tommy