Are AGM decisions valid if meeting notice was late?

Not sure about how things work in WA but elsewhere you might find that it makes no difference unless someone is
“breached” under the by-laws and challenges the complaint on the grounds that the by-law wasn’t validly passed.

You could fix that later with another general meeting held specifically to endorse the by-laws agreed upon at the AGM. However the current law and future laws say that decisions made at a meeting where there was  accidental failure to give proper notice, still stand. I think most authorities would accept that missing by a day was accidental.

Schedule 1, Section 11 (5) of the WA Strata Titles Act 1985 says this:

… accidental omission to give the notice to any proprietor or to any registered first mortgagee or non-receipt of the notice by any proprietor or by any registered first mortgagee does not invalidate any proceedings at any such [general] meeting.

Section 129 (3) of the new WA strata act says this:

Accidental omission to give notice of a general meeting to the owner or first mortgagee of a lot or non-receipt of the notice by the owner or first mortgagee of a lot does not invalidate any proceedings at the meeting.

By the way,  the new Act has been passed but not proclaimed as yet, as they are waiting for the supporting regulations to be approved.  This is scheduled to happen in the third quarter of this year.  So it’s not law but it does indicate where the law is going.

In summary, it would be a brave and possibly foolish owner who decided to ignore the decisions made at the meeting  because the notice was a day overdue.

You can read all about WA’s impending strata reforms HERE.