If my reports in one of my companies do not balance. i.e. net profit is different to net profit in balance sheet also cannot print trial balance with full year costs

We can work together and figure this out, lorette.

Normally, the net income amount on the Profit and Loss report always matches the Balance Sheet. Let's carefully review the issues that may be causing the mismatch. Carefully review the Profit & Loss statement. Compare the P&L and Trial Balance amounts account by account to find out if any are missing.

If P&L net income is greater than the balance sheet, chances are an Expense account is missing from the P&L. If P&L net income  is less than the balance sheet, chances are that a Revenue account is missing from the P&L, or that an Expense account is duplicated in the P&L.

Regarding the Trial Balance let's check the Report period to make sure it prints the full-year costs. 

Need help customizing your reports? You can follow through with this article: Customise reports in QuickBooks Online.

Please let me know if you have any other questions. I'm here to help.