Meetings often run on and when they run over lunchtime the employer may provide a sandwich lunch as a gesture of goodwill. Many employers would not even think about the possible tax consequences of such a gesture, but such an oversight could land them in hot water with HMRC.
The exemption for subsidised meals does not apply as meals are not made available for all employees. Consequently a tax charge will arise on the benefit. Most employers do not want employees to be taxed on the provision of the occasional sandwich. Consequently, it is advisable to settle the liability by means of a PAYE Settlement Agreement.
The tax implications of sandwich lunches are easily overlooked. HMRC know this and it is often something they look for in a PAYE.