I have just started work experience and was handed a client and told to try and prepare the annual report and left to get on with it!

It doesn't appear that this client keeps their original invoices. On their banking page I can only match to the statements that their customers have sent in with payment. So when I tried calculating the debtors by comparing the bankings to what I thought was the invoices, it didn't work. I have more bankings than statements and a few clients just make BACS payment without paper.

How do I calculate the debtors then?

Also, I know I will need to calculate accruals and prepayments, I have seen some utility bills, which I can calculate in theory so practice will be similar I hope.

I can't do depreciation yet as I am waiting for estimated value of assets.

What else do I need to do to prepare the statements?

Have you tried interviewing the client, someone knows what is owed and what is collectible, that is unless your client is a complete fool. To calculate debtors at a particular date you backtrack from payments received after that date, ask the client what his terms are and how his debtors pay. In this case precision may not be possible but much knowledge can be gained by observation and asking the right questions