Wise сообщает на своем сайте:

each customer is eligible for protection under the Estonian Guarantee Fund (GF) up to a value of 20,000 EUR in Europe

Это пишет Wise Europe SA. Там же указано:

We are not a bank, which means we don't lend out our customers’ money to people or businesses. This also means our payment services aren't subject to the Belgian Deposit Guarantee Scheme