Cost estimate and final invoice

Reduce the invoice at each item to the maximum 24% surcharge where it was exceeded. Inform the company of the new figures and see what happens. (Of course, this must be done by the person responsible, not you as the auditor.)

Reduce the invoice at each item to the max. 24% surcharge where it was exceeded. Inform the company of the new figures and see what happens.
(Of course, this has to be done by the person responsible, not you as the reviewer.)

I correctly increased the items that were below 24% and reduced those above 24%. My calculation still results in a lower amount. The company's invoice is completely correct in content. The items are correct, what was done is invoiced, sqm, m, and quantities are correct. What was not done does not appear.
But mathematically, no matter how you calculate, you do not get to the total sum. But anyway, I see that this is a complex matter.

Would calculate it the same way as you. Unit prices from May 2018 * 1.24 and multiply that by the actual quantities performed. Add up the products of all individual items, subtract the 2% discount and finally add 19% VAT = amount payable.

If the company has a problem with that, they will get in touch.

Edit: And feel free to also check the quantities randomly

Agree with , only the factor 1.24 is not correct. It is 1.2495 (1.19*1.05). We have built in individual trades ourselves. It was a completely normal procedure that the invoice of a trade was first checked by the architect, especially the quantities, and then possibly changed again by me. This is acknowledged and paid. No drama. If a trade has problems with that, they have to prove the quantities, which occasionally happened.

It is 1.2495 (1.19*1.05).

Wooden eye, be vigilant! He is right.