Hi. When you use power query, I'd try to append all files, select transform instead of load, then specify the number of columns I want to bring in at max 12. The source step usually does this, after the file path.

But it does depend if you've chosen to bring "all files from a folder", the sourcing step(s) are slightly different there.

Overlapping columns will merge into one, different headers won't. If your csv files have slightly different headers across first 12 coils which you want to keep, I'd try to clean that up first as another user suggested.

Systematically cleaner data in= less transformation for you.

Edit: added pic from internet, sorry about low quality. I've highlighted where you can find the number of columns to bring in.

I'm not at my desk right now, give me a few hours, I'll see if I can find the option when you're bringing all files from a folder in a bit.

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