In case your BRP number has 3 alphabets and 6 digits it wont be accepted in the online form. The way around as suggested by UKBA authorities is as follows "Please select the option “Already with UKBA” and then, in your covering letter explain that the form wouldn’t allow the BRP reference to be...

I have a similar problem. My Biometric Residence permit has 3 alphabets and 6 digits. This is not accepted as a correct format while filling online Tier2 application. Can anyone suggest anything?