someone's word is their bond

(one's) word is (one's) bond

One always keeps one's promises. I promise that I'll be there in time with the money for the deposit: my word is my bond.
See also: bond, word
Farlex Dictionary of Idioms.

someone's word is their bond

someone keeps their promises.
A variant of this expression, now rather dated, is an Englishman's word is his bond .
See also: bond, word
Farlex Partner Idioms Dictionary
See also:
  • (one's) word is (one's) bond
  • one's word is bond
  • your, his, etc. word is your, his, etc. bond
  • bond
  • word by word
  • from the word go
  • keep (one's) word
  • keep one's word
  • keep word
  • false friend