Closing out a worksheet with extended references

Good day.

The subject of this request may not be accurately stated
as I am not sure of the correct terminology to use.

I have a worksheet that creates a Quarterly Return
Worksheet required by the government (ST50/ST51). I also
have worksheets that track my daily sales and tax
collections. The worksheet in question looks at monthly
totals of my sales and tax collections to fill in the data
for the quarterly return.

My question is this; every time that I open the quarterly
return worksheet, it states that the data needs to be
updated since 90% of the form is formula references to
other worksheets. I realize that after updating the form,
I can save the data upon exiting Excel. Even after saving
on exit, the next time I open the worksheet, the same
question appears.

Is it possible to somehow "close" the worksheet at the end
of the year and "freeze" it so that no other changes can
be done and the worksheet will become a reference for the
future rather than a working worksheet?

If there is data missing for this issue, or not enough
detail, please e-mail me directly and I will provide any
data necessary.

Thanks in advance to all who respond,
Danno...