Yellow boxes (or yacht boxes) used for depositing C1331 forms are emptied by UK Border Force staff working in flexible teams. They are emptied as and when staff are deployed to those locations where boxes are present.
When the forms have been collected from the yellow boxes, they are sent to a central point for processing and analysing.
The National Yachtline advises yachtsmen to send the C1331s to a single point in Dover where the data are checked and recorded. The information is then forwarded to direct taxes to follow up as appropriate.
HMRC are in the process of updating public Notice 8 Sailing Your Pleasure craft to and from the UK to reflect this current practice.