I called +441619752000, saying I had Hilton honors status and wanted to match with marriott. I was told there were no status match but he would enrol me for an 8night challenge within 3months to attain Gold Marriott status or 60nights to attain Platinum status. Note: you can only choose one of the status so I went with Gold so i can start receiving benefits ahead from my 8 stay rather than wait for 60nights. He didnt ask for any proof, just enrolled me straight away.