4. Open another bmi account with your maiden name. While logged in under this account go to the household accounts section and invite the account with your married name to join your household.

Once this account is linked to your household transfer all the points To the account with your maiden name.

From this point you can use combine my Avios to get them over to BA.

It's easier to do it this way.

Comments on your suggestions

1. Would cause needless hassle as you'd have to prove to BA that you were the same person (copy of marriage certificate, etc) to change your name and to credit miles the name on the booking must match the name on the account.

2. Might be possible but if they require proof it may take a long time to process due to limited staffing at bmi now.

3. The household accounts on BA don't allow transfer of miles between them (unlike bmi) only pooling of miles so you'd need to keep both accounts active. If BA then noticed there were effectively two accounts for the same person they'd be in their rights to close your account for breach of the rules.