Once a year suits most homes
For a typical property, an annual clean is enough. Late autumn is the usual choice, once the leaves have come down but before the heaviest winter rain arrives.
When twice a year makes sense
Properties surrounded by trees can fill a gutter in a single season. If you have overhanging branches, conifers nearby or a north-facing roof where moss thrives, two visits a year is often more sensible than one.
The same applies to homes with shallow or older guttering, where it takes less debris to cause an overflow.
Let the gutters tell you
Watch during heavy rain. If water is coming over the front edge anywhere along the run, the gutter needs attention regardless of when it was last cleared.