I’m not sure if this is a different manifestation of the same bug or something else but I don’t seem to be able to find any relationship between the start_index and items_per_page parameters and the results returned. In fact I’d say they are both ignored.
Example 1:
https://api.companieshouse.gov.uk/search/companies?q=Auto&start_index=30
JSON results end with:
"start_index":0,"kind":"search#companies","page_number":1,"items_per_page":20}
Example 2 (here using start_index as a multiple of items_per_page):
https://api.companieshouse.gov.uk/search/companies?q=Auto&items_per_page=10&start_index=20
ends with:
"page_number":1,"items_per_page":20,"start_index":0,"total_results":19236,