You can issue tax receipts and thank you letters to donors and donor referrers by extracting tax receipt and thank you letter data in .CSV and .XML, which you can then use as part of a mail merge in the document editor of you choice.
When users create an order containing donations/gifts, they must select a tax receipt template and a default thank you letter template for the receipt contact. This section is used as criteria for printing tax receipts and thank you letters.
For information on printing tax receipts and thank you letters and voiding or re-issuing receipts, refer to Generating a Tax Receipt and Thank You Letters and Utilities - Pledges.