Non-US Nexus: Setup>Accounting>Tax Codes >Edit a Tax Code > Available on Drop Down List shows only one option

On the Tax Code record, Available on Field shows three options:

a. Sales

b. Purchases

c. Both

If users can only select one option on the Available on field when editing an existing tax code, consider that the same may have been already used in a transaction. As an alternative solution, perform the following:

1. Navigate to Setup > Accounting > Tax Codes.
2. Select the Tax Code in question.
3. Change the Tax Type and notice that the Available on field is left blank.
4. Choose Purchases.
5. Assign back the original Tax Type.