I have never had any delays with smaller amounts on Wise. I can't comment on what Wise is likely to do or not do with a txn in, I am guessing, 6 figures USD equivalent. They do have a web page dedicated to the topic https://wise.com/large-amounts/, where indeed the additional documentation is mentioned. My guess: If Wise deems a transaction suspicious or warranting additional questions, then so will a bricks-and-mortar traditional bank. One may have some KYC edge over the other, if you have been their client for a significant amount of time, but not by much. Likewise, any follow-up and communications from each of these institutions will likely be similar and very limited, as clear AML regulations prevent these institutions from even telling you that it is an AML-related issue. My suggestion: Go with the better rate, but give yourself extra time.