The stamp Act of 1783 in England charged 3d for an entry in the parish register and was repealed in 1794. Paupers were exempt from this duty. some parents did not baptise their children because of this tax and it must be born in mind that children baptised just after 1794 might be older than expected as their parents were waiting until the act was repealed.
See, Steve, I have learned something in my IHGS genealogy course. That was England so as Ellie says so it must have been Scotland too.
Barbara