British Airways bought BMI back in April. The airline withdraw from the Star Alliance on that date, but the Star Alliance benefits i.e. lounge access and extra luggage allowance as well the ability to earn and redeem on Star Alliance except Lufthansa Group of airlines will continue until the end of May.
Now, you can transfer your BMI Diamond Club status Silver/Gold to British Airways Executive Club Silver/Gold status. BMI and BA haven’t publicized how long this offer will last, but I would expect it to go to the very end of BMI’s existence that is at least to the end of October.
You need to fill out the form on BA’s website and include your BMI Diamond Club as well as your BA Executive Club numbers. BA will then confirm the status of your BMI account and match it to the Silver or Gold level.
The BMI status transfer to BA is valid for 12 months. If you apply i.e. after 8th of May the status will be valid until the end of June the following year. You lose a month if you apply between the first of month and 8th. You need to qualify for the BA status on your own during the membership year period.
BA’s Silver is comparable to AA’s Platinum status (Oneworld Sapphire). It will give you access to business class check in desks and lounge access if you are ticketed in economy. BA Gold is comparable to AA Executive Platinum (Oneworld Emerald). You will get first class check in and first class lounge access regardless of the ticketed cabin.
Star Alliance doesn’t have equivalent status to Oneworld Emerald. Star Alliance Gold i.e. BMI Diamond Club Gold is closed to Oneworld Sapphire status than Emerald.
I am still crediting some Star Alliance flights to BMI’s program and expect to make it back to Gold before the end of the month. I will do the status transfer to BA’s Executive Club later in the year. I have lifetime Platinum status with AA that gives me the Oneworld Sapphire benefits.