The situation with British Gas (Centrica) has been very different in our experience. We have now received two FIT cheques from them for our solar panels installed 8 months ago (Nov 2011). The most recent payment has addressed some of the criticism that I'd felt with the first payment - namely that they cheque came without any supporting documentation or explanation of the calculations used.
The new British Gas Feed in Tariff advice note is very comprehensive and details the payments made under the Generation Tariff and Export tariff with a split covering the 31 March when the tariff rate changes.
|British Gas FIT payments - payment summary|
To change or submit your FIT Feed in Tariff readings to British Gas look here