Can the Consultant add fee to his expenses under the NEC3 PSC contract?

Can the Consultant add fee to his expenses under the NEC3 PSC contract?

The PSC contract is silent on “Fee” or “fee percentage” that is found in the other contracts with in the NEC3 suite. The Consultant is paid expenses as set out in the Contract Data and in line with clause 50.3. However I am not sure that this precludes Consultant or Employer from adding statements into the Contract Data that say for example “Accommodation £50 per night plus 10%” or a number of variant on this theme. Likewise i have seen Employer use similar wording to cap the value of expenses or link them to HMRC mileage rates, etc.