https://www.slab.org.uk/guidance/fees-payable-to-sheriff-officers-and-messengers-at-arms/
The fees payable to sheriff officers are regulated by the Table of Fees payable to Sheriff Officers (Act of Sederunt (Fees of Sheriff Officers) 1990 (SI 1990 N0 381).
The use of messengers-at-arms and sheriff officers is only considered appropriate where: