G/L account & requires a valid tax code

What causes this issue?

The master record of account &v1& requires you to enter a valid tax code
in each item for this account in company code &v2&.
A tax code must always be entered for tax accounts.

System Response

Error message

How to fix this error?

Enter a valid tax code.
If the document was not created directly via an accounting transaction,
then the preliminary work area must make sure that a valid tax code is
transferred to the accounting interface. You must therefore check the
Customizing settings of the relevant application to ensure that a
corresponding tax code is also determined and transferred when a line
item is created for this account.
In Customizing for Accounting, you can also define two tax keys that
flag the items as non-taxable for transactions not relevant to tax.
These indicators are then set to the corresponding items by the
accounting interface.
If necessary, the G/L account can also be set so that the tax code is
not a required entry when posting transactions not relevant to tax.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.