Wahaca has tightened up its policy on walk-outs, after a waiter was reportedly told to pay part of the bill when customers left without paying.

The restaurant chain previously only made servers cover part of the bill in rare cases of “real negligence”, and said the incident was caused by an “internal communications issue” which has now been resolved.

Wahaca said waiters would no longer have to pay any element of the bill when this happens, unless it was suspected the waiter was “complicit” in a walk-out, which would be investigated.

Co-founder Mark Selby said after the incident Wahaca had decided its policy needed a “clearer direction”.