AA-46 Traveling charges Reimbursement

Dear All Respected Members,

Happy New Year to All.

please educate me on following:

suppose, our client gave us a service order in which they mentioned traveling charges separately.

we spend only Rs.2,000 for traveling but in service order Rs. 20,000 were allowed us.

client representative asked me to claim full Rs. 20,000 for traveling.

in this condition, how can we record in our accounts when we spend less from allowed amount?

Further, please let me know will extra amount be considered as income? and what would be it's accounting?

Thanks for your precious time and efforts to reply this query.