do stat decs expire?

[k8bug79]

Hello, we have started to collate bits and pieces for my spouses visa. A few friends have done us declerations regarding our relationship and my ex is in the process of signing a stat dec to say my daughter can come with me. But we are now looking at delaying a few years becasue of work commitments and finances. Will the declarations expire? Obviously I would provide some for the interim period between what they cover and when we apply. My best friend from childhood is yet to do one for us so we can leave hers, but two friends local to where we live and who see us in our day to day lives have already written and had them countersigned. WIll this be an issue?

Thanks