adverb
therefor
thair-FOR/ðɛrˈfɔr/
For that thing or purpose.
The gardener requests repair of the cracked watering can and offers payment therefor.

Etymology
There points back to something already mentioned, while for expresses the relation 'for the sake of' or 'on account of.' Together they give 'for that,' referring to the thing or purpose just named.
In context
customer shall fail to pay any charge within 30 days of any invoice [therefor]
he returned a large sum of money and was rewarded [therefor]
More examples
- The applicant states the requested change and the reasons therefor.
- The buyer accepts the goods and agrees to pay therefor.
- The agreement describes the work and provides compensation therefor.
Similar words
- for that
- Expresses the same meaning in everyday rather than formal legal language.