Once packet 3 has been returned to the Embassy and processed, a further packet (known as as Packet 4) will be sent out by the Embassy. This will detail the interview date and will contain a payment slip which can be paid at any Barclays bank (without a fee) or any other bank with a fee. A portion of this payment slip whould be taken to the interviw to prove the visa fee has been paid. The embassy in London does not accept payment on the day of the interview.
Mark