What happened when Britain requisitioned a foreign warship

Was a country compensated when Britain requisitioned a warship it had ordered from a British yard?

Yes. The buyer could receive money and, in some cases, the ship after the war.

When the Royal Navy took over a foreign warship under construction in a British yard, the purchasing state was compensated, commonly with money and sometimes through the return of the ship once the war ended. The later Agincourt discussion therefore has an important procurement context: wartime requisition did not simply erase the original buyer's claim. Private export construction could become part of national mobilisation while contractual obligations survived.