The p in receipt is silent, and it was put there on purpose. English took the word in the late 1300s from Anglo-French receite and spelled it receit for a century or more — which is exactly how it sounded. After about 1500, scholars restored a p to show that the word descends from Latin recepta, from recipere, "to receive." The pronunciation never followed.
What makes receipt the best of these cases is the company it failed to keep. Conceit, deceit and receipt all come from the same Latin capere, "to take," and at various times a p was restored in all three. It stuck only in receipt. So English now spells three words from one root two different ways, for no reason except which respellings happened to survive. The b in debt and doubt is the same intervention; the difference is that nobody tried it on debit.
receipt (n.) late 14c., receit , "act of receiving;" also "statement of ingredients in and formula for making a potion or medicine" (compare recipe ); from Anglo-French or Old North French receite "receipt, recipe, prescription" (c. 1300), altered (by influence of receit "he receives," from Vulgar Latin *recipit ) from Old French recete. This is from Medieval Latin Latin recepta "thing or money received," in classical Latin "received," fem. past participle of recipere "to hold, contain" (see receive ). The classical -p- began to be restored in the English word after c. 1500, but the pronunciation did not follow. Conceit , deceit , and receipt all are from Latin capere ; the -p- sometimes was restored in all three of them, but it has stuck only in the last. The meaning "written acknowledgment for having received something specified" is from c. 1600. also from late 14c.
receipt came in through Latin, and its spelling follows that family's conventions.
What gives it away on the page
| silent letters that spoil the pronunciation | Renaissance scribes inserted them to display a Latin ancestor. See the caveats below — this is the one cue that is often a lie.debt, doubt, receipt, salmon |