phonenumber is an R package that converts English letters to numbers or numbers to English letters as on a telephone keypad.


When I recently posted some of my Turbo Pascal Stuff, I found an incomplete program that was supposed to do this. I was active on BBSes and, though I don’t recall the reason, I wanted a way to determine the possible words spelled by the BBS phone numbers (and/or how to determine what phone numbers correspond to words/phrases). I never got around to finishing the second part (numbers to letters) in Turbo Pascal, though.

I decided to create this functionality in R for three reasons:

  1. to see if I could write the functions
  2. to learn to publish a package to CRAN
  3. to serve as a possible pedagogical example for others as it involves working with lists, splitting strings, and the expand.grid function.


  • phonenumber is available on CRAN and can be installed accordingly:

  • You can also install phonenumber from GitHub using the devtools package: