I would like to reclassify the customer in multiple transactions -

Hey there, @JBSPS. 

Thanks for coming to the Community with your question about reclassify in QBO. 

Before giving you a solution, are you referring to trying to change every customer on multiple transactions to another? 

In the meantime, check out this guide about reclassifying or moving multiple transactions in QBO. 

I'll be waiting for your response!