The following information is taken from the Dictionary of the Older Scottish Tongue, available online at http://www.dsl.ac.uk/index.html. This is a work in progress.
| Spelling | Number | Dates & headers |
|---|---|---|
| Borthuik | 3 | 1517 (canoner); 1569 (curie); 1584 (apperant) |
| Borthwik | 3 | 1517 (artailȝe); 1523 (camp); 1526 (calmis) |
| Borthik | 2 | 1530 (commoun); 1531 (clos) |
| Borthek | 1 | 1530 (clos) |
| Borthwick | 1 | 1538 (clip) |
| of Borthwik | 1 | 1492 (cautioun) |