A pre-sue report is a factual assessment of a prospective defendant, prepared before a claim is issued. It confirms identity and current address from checkable sources, establishes solvency and trading status, identifies any recoverable interest, and concludes with a view on whether litigation is commercially worthwhile.
It should be commissioned at the point the decision to sue is being made, not after judgment. Ordered early it costs a fraction of a court fee and frequently changes the decision; ordered late it usually confirms why an enforcement attempt failed.