- Letters must not contain any letter, note, or document which has the character of actual and personal correspondence, addressed to persons other than the addressee or persons living with him.
- Articles other than sealed registered letters must not contain coin, bank notes, currency notes, negotiable instruments payable to bearer, platinum, gold or silver, manufactured or not, precious stones, jewels and other valuable articles.
- The sender of a packet, prepaid at the letter rate of postage and which by reason of its size or make up would be mistaken for another class of packet, is recommended to write the word "Letter" on the address side of the packet.
- Letters containing perishable biological substances may be exchanged only between officially recognized Laboratories of countries which have agreed to admit these items provided that such letters bear the special violet coloured label and are packed according to the special conditions given below:
- Perishable biological substances consisting of living pathogenic micro-organisms or of living pathogenic viruses shall be enclosed in a bottle or tube of thick glass, well Stoppered, or in a sealed phial. This container shall be impermeable and hermetically sealed. It shall be surrounded with a thick and absorbent material (absorbent cotton wool, swan’s down cloth or flannelette) wrapped round the container several times and bound both above and below it so as to form a sort of cocoon. The container so wrapped shall be placed in a solid, well fastened, metal box. The absorbent material placed between the inner container and the metal box shall be of sufficient quantity to absorb, in case of a breakage, all the liquid contained, or capable of being formed, in the inner container. The metal box shall be made and fastened in such a way as to make any contamination of the outside of the box impossible. The metal box itself shall be wrapped in cotton or spongy material and enclosed in its turn in a protective box in such a way as to prevent any movement. This outer protective box shall be hollowed out from a block of solid wood, or shall be of metal, or may be of a material and construction of equivalent strength, and furnished with a well fitting lid fastened so that it cannot open in course of transmission. Special provision such as drying by freezing or packing in ice shall be made to ensure the preservation of substances sensitive to high temperatures. Air transmission, which entails changes in atmospheric pressure, makes it necessary that the packing should be strong enough to withstand these variations in pressure. Moreover, the outer box (as well as the outer wrapping if there is any) shall be furnished on the side which bears the addresses of the officially recognised laboratories sending and receiving the item, with a violet coloured label with a special symbol and the following indications: "This label can be used only by officially recognised laboratories"; "Perishable biological substances (for medical use)"; "Dangerous: Not to be opened in transit"; "No commercial value"; "Packed in accordance with the safety regulations of the international postal service";
- perishable biological substances which contain neither living pathogenic micro-organisms nor living pathogenic viruses shall be packed in an inner impermeable container with an outer protective container and with absorbent material placed either in the inner container or between the outer and inner container; this material shall be of sufficient quantity to absorb, in case of a breakage, all the liquid contained, or capable of being formed, in the inner container. Moreover, the contents of the inner as well as the outer container shall be packed in such a way as to prevent any movement. Special provision such as drying by freezing and packing in ice shall be made to ensure the preservation of_ substances sensitive to high temperatures. Air transmission, which entails changes of atmospheric pressure, makes it necessary, if the substances are packed in sealed phials or well stoppered bottles, that these containers should be strong enough to withstand variations in pressure. The outer container, as well as the outer wrapping of the item shall be furnished, on the side which bears the addresses of the laboratories sending and receiving it, with a violet coloured label with a special symbol and the following indications: "This label can be used only by officially recognized laboratories"; "Perishable biological substances (for medical use); "Dangerous: Not to be opened in transit"; "No commercial value"; "Packed in accordance with the safety regulations of the international postal service".
Dutiable Articles by Letter Post – (Green Label Letters)
Articles liable to Customs Duty may be sent in packets prepaid at the letter rate of postage to those countries which have agreed to admit them. A green label, obtainable at any Post Office, giving particulars of the nature, weight and value of the articles must be affixed to the address side of each packet; and in addition if the country of destination so requires, one or more Customs Declaration forms must be securely fastened to the outside of the article by a string tied crosswise or enclosed in the packet. In the latter case only the upper part of the green label should be affixed to the packet. Dutiable articles may also be sent in small packets to the countries where that service obtains (see Small Packets). To other countries dutiable articles may only be sent by Parcel Post or in Insured Boxes. Dutiable articles sent otherwise may be returned, subjected to fines or confiscation, according to the laws of the country of destination. Printed matter is however not debarred from transmission by Printed Paper Post on account of liability to Customs Duty.
Weight and Size
- Letters to Commonwealth Countries must not exceed 2,000 grams in weight, length, width and depth combined must not exceed 900 mm but the greatest dimension must not exceed 610 mm in roll form length and twice the diameter shall not exceed 1,037 mm, but he greatest dimension shall not exceed 889 mm.
- Letters, other than those in roll form, addressed to any place outside Sri Lanka shall be not less than 140 mm in length and 90 mm in width.
- Articles with a size less than the minimum dimensions are nevertheless admitted if they bear a rectangular address label of cardboard, or strong paper measuring not less than 160 mm by 40 mm.
The postage on a letter may change from time to time without notice. Please see Foreign Postage Rates.