Try this in A3:

=IF(OR(A1="",A2=""),"",A1+A2)

That checks for both A1 and A2 being empty, and if either of them are
then the formula will return a blank. If you only want to test for A2,
then you can do this:

=IF(A2="","",A1+A2)

No need for SUM.

Hope this helps.

Pete



On Dec 8, 12:53*pm, Ric Crombie wrote:
Hi there, some help needed please for probably a simple problem.

Lets say I have a value in cell A1. A2 is blank for now and the total
of the SUM will be in A3.

How can i get it so that A3 is blank until A2 is filled in.

Any would be appreciated