Definition
A number assigned by the tax authorities to every person and corporation. In Peru, the tax number is known as the número de registro unico de contribuyentes (RUC).
Use
The tax number is used for reporting to the tax authorities and for business documents.
You maintain your customers’ and vendors’ tax numbers in their master records, in the Tax code 1 field on the Control data tab (customers) or on the Control data screen (vendors) (see
Creating a Customer Master Record Centrally and
Creating a Vendor Master Record Centrally). You maintain your own tax numbers in Customizing for Financial Accounting, under Financial Accounting Global Settings ®
Company Code ®
Enter Global Parameters, but before you can do so, you must set up this field as described in
Setting Up the Tax Number Field.
Structure
In Peru, the tax number consists of eight digits, for example, 10001340. The last digit is a check digit.

You can set the system so that it automatically checks the tax numbers of any Peruvian customers or vendors that you enter against the check digit (see