For a bank rec, ask for the exceptions list, not the reconciliation

Don't paste a whole bank statement and ledger into a chat and ask it to reconcile them. It's slow, it can miscount, and you'll never know which lines it skipped.

Do the matching where you can see it. Use your normal lookup on amount and date, and get everything that pairs up out of the way. What's left is a much shorter list of awkward lines, and that's the part worth a second opinion.

Paste only those, from both sides:

Below are the unmatched items from our bank statement and our ledger
for [MONTH]. For each unmatched item, on either side, suggest the
likeliest reason from this list, or say "unknown":
- timing (cleared in a different month)
- amounts that net off (two ledger lines make one bank line, or the
  other way round)
- a bank charge or interest we haven't booked
- a duplicate entry
- a typo in the reference
Show the evidence for each: the matching amount, date or reference.
If nothing fits, say "unknown". Don't force a match.

Bank: [PASTE]
Ledger: [PASTE]

A short list is where a model does well. It'll see that £1,450 on the ledger is £1,000 and £450 on the bank faster than you will with a tired eye. Asking for the evidence and allowing "unknown" stops it making up a tidy story for every line.

Everything it suggests is still a query or a journal that somebody checks. It's a hint, not a posting.

Take account numbers and names out first unless the tool is approved for finance data. And see reconcile before you summarise for the wider habit.