What happens when this goes wrong?
Every other page shows this payment working. Here you choose what breaks, and follow the damage — because a hold, a return or a missed cut-off is the system working as designed, and reading one calmly is the job.
Pick a failure above. Nothing here is invented — each one is a reason code this rail really uses, at the step where it really strikes.
One collection through one three-working-day cycle with direct participants. Real Bacs processing batches large volumes, often runs through a sponsoring bank, and carries many return and amendment reason codes beyond the single ARUDD path shown. Every failure here is authored on Bacs Direct Debit, with the sources that back it.