Our abattoir does require them, but it's all done electronically between LIS and the vet as far as I can tell.
Our vet charges £40 per visit to do them, and will attest any number of species on one visit. They just need to see the actual animals which will be going off in the next 12 months, so it has to be timed for when we have all the lambs calves and weaners we'll be sending, and before we want to send any of them!
We also, of course, make use of the free farm callout, to have the vet check anything we are concerned about or do any procedures we need

.
And our vet won't prescribe antibiotics over the phone unless they've been to the farm within the previous 6 months, so with a bit more care with planning dates, between the VAN visit and the annual TB test we stay covered for that too.