The letter sheet issued by the post office is a folded piece of paper. The cover is printed with postage symbols, and the inside is used for writing correspondence. It is a special mail format. All sides must be properly sealed when sending.

Any individual or manufacturer with ROC nationality is allowed to self-print them but needs to apply for permission. Just attach two copies of your letter sheet or aerogramme design, both folded and unfolded, and send the application to Chunghwa Post Co., Ltd. (address: No. 55, Section 2, Jinshan South Road, Daan District, Taipei 10603).

Self-printed domestic and international letter sheets paper quality and specifications:
(1) Domestic letter sheet: light colored woodfree paper of 100 grams per square meter.
(2) International aerogramme: light blue woodfree paper of 84.4 grams per square meter.
(3) Standard size: 215*284 mm (including sealing) after unfolding; 90*184 mm after folding, with error tolerance of 2 mm.
(4) Allowed size: up to 3 folds (4 folds if there is a back cover copy registration return symbol), the maximum size after folding is 110*220 mm, the minimum size is 90*140 mm, with error tolerance of 2 mm.

(1) There should be the name of the printer/seller and permission number by Chunghwa Post Co., Ltd. on the cover or the back of a self-printed letter sheet.
(2) Domestic letter sheet
Vertical type: front side: upper right corner are the red zip code number boxes in line with post office standards; upper left corner is the stamp box with wavy marks; below the stamp box is a “domestic letter sheet” print.
Horizontal type: upper right corner is the stamp box with wavy marks; below the stamp box is a “domestic letter sheet” print. There should be dotted lines in proper positions to guide the sender to write down his zip code, name and address in the right place. Both vertical and horizontal letter sheets should be printed with warnings including “Wrongly written zip code will result in this letter sheet sent with ordinary letter postage” and “A letter sheet with any enclosed material will be sent with ordinary letter postage.”
(3) International Aerogramme
On the front side lower left corner should be printed “AEROGRAMME” and “PAR AVION”; upper left corner should print sender's name and address. On the back, print “An aerogramme with any enclosed material will be sent via surface instead.”

Enter http://www.post.gov.tw/post/internet/U_english2/default.jsp ; click on “Postal Services,” click “Postal Services,” and then on “EMS Track Service” to view delivery information.

1. According to Article 6 of the Postal Law, the exclusive post office service includes documents in the nature of letter, postcard or other correspondence.
2. The definitions documents of letter, postcard or other correspondence are as follows:
(1) Letters, special letter sheets, self-printed letter sheets and postcards.
(2) Bills, refund notices, bank statements and certificates, etc., from various financial, insurance, securities, telecommunications, video, hydropower, gas and other institutions.
(3) Various types of fines, tax returns and withholding tax statements.
(4) Unified receipts, receipts and stubs that are filled out with specific personal information and are not blank.
(5) Prized contest documents, questionnaires, registration forms, resumes, checklists and application forms that are filled out with specific personal information.
(6) All types of documents containing personal information and are attached with debit cards, credit cards, stored value cards and computer IC cards.
(7) Withholding tax statements meeting Ministry of Finance format standards, filled student report cards, and school attendance certificates are legally post office's operation, but Chunghwa Post Co., Ltd. is willing to regard them as printed matters and let private delivery service share the operation.

For domestic mail, the inquiries will be accepted within a period of six months from the date on which the item was posted.