I know that Wise can be contacted for sending, like you mentioned, 5 or 10 million Pound. They will provide the necessary documentation for the proof of the source of the money. The receiving Thai bank can't see the orign of the money, like selling a house, winning a lottery, criminal activities, historical family capital, etc. If you decide to sent the money in fractions of the total sum, let say 500,000 per month, the bank/tax department can assume you have a salary from your home country or, more serious, case of money laundering. There is a change that alarm bells will go off if sending right away.

Also the receiving bank must be notified. Leave that communication to Wise. These amounts are not common for private banking. Better save than sorry.

@Jay ******

The 180 days is a local tax issue.

@Wayne *******

I don't know also. Perhaps Estimated Time of Arrival?