When it comes to financial transactions, the term "full amount" refers to the total sum of money owed or paid. However, there are several synonyms that you can use instead of the phrase "full amount". Some common synonyms include "total cost", "entire fee", "complete payment" or "final price". Other options include "whole amount", "maximum sum", "ultimate bill" or "total expenditure". Additionally, one can use phrases like "the full sum to be paid" or "the complete balance owed". Regardless of which synonym you select, always ensure that it accurately reflects the total amount being discussed.