Proof of work history - validity expires?

[cracked]

Wife is concerned that her letters from employers will expire, is there an expiry date , as with IELTS?

 

[Baahubali]

With past employers, no, but it is recommended to get a fresh letter (within a month or so) from current employer.

 

[Indi- canada]

Wife is concerned that her letters from employers will expire, is there an expiry date , as with IELTS?

there is no expiry date for experience letters unless and until there are changes in current designation. like promotion, changes in duties and responsibilities, increment. so old letter will not have any issues.

however its always better to provide fresh letter in case of ITA. as CIC give you 90 days to arrange your documents.
in case if it is PNP old letter will do as most of the PNP's are unpredictable. they open and close at any time without any prior intimation.
best luck.