You can withdraw cash from any cash machine in your home country or overseas that supports Mastercard, but please look out for any fees that are applied by some ATM operators.
If the ATM asks whether you would like to complete the transaction 'with conversion' or 'without conversion', you should always choose 'without conversion'. As a rule of thumb, you should always opt to be charged in the local currency of the country you’re in! If you’re in Thailand choose Thai Baht, in Spain, Euros or in the United States, US Dollars. If you choose 'with conversion', the ATM provider can apply their own exchange rate, which is not the interbank rate.