Self employed contractors & travel expenses - evidence?

We have several self employed contractors who invoice us each month for inspections and audits they complete. We pay an agreed fee for each type of inspection or audit and in addition to this they can recharge any associated travel expenses made up of mileage paid at HMRC rates of 45p per mile or 25p per mile, accommodation, subsistence and other travel costs (parking or flights) etc, My question is should the contractor provide us with copies of receipts as back up to the travel expenses they are claiming so we have these for our records? Or should we just check the cost they are claiming is reasonable? Thank you

Hi Sarah Perrett,
That is a matter between you and the subcontractor in order to keep your own records correct.
Thank you.