Among the most spectacular items of mail from the Philippines are those bearing the adhesives of India, Hong Kong or Straits Settlements. Not only are they sought after by collectors of Philippines, but also by collectors of those other countries.

Until the Philippines joined the UPU in 1877, the adhesives of the Spanish Philippines were not accepted for payment of mail to foreign countries. They could only be used for postage on internal mail and on mail to Spain and her colonies.

In 1845, the British P&0 company extended its steamer service to Hong Kong. This reduced the travel time to two months for a letter from the Far East to Europe, whereas previously it had taken about five months by sailing ship. Furthermore the service was regular, with a steamer departing every month from
Hong Kong.

This had an enormous effect on the carriage of mail from all places in the Far East. From the Philippines, virtually all mail to Europe and the United States was carried by the P&.0. There were two ports where mail from the Philippines could feed into the P&0 service: Hong Kong and Singapore. 

Mail to Spain was usually placed in a closed bag by the Manila Post Office. The bag was carried to Hong Kong (or sometimes Singapore) and then by P&.0 steamer to Gibraltar, where it was handed over to the Spanish Post Office. Such mail had no British markings, having been carried in a closed container.

Mail to the rest of the world was nearly always carried using the British postal system. Such mail was carried from Manila to either Hong Kong or Singapore. The stampless mail could, at various times, have been paid or unpaid.  Mail from the Philippines could still be sent stampless, even for the first few years after the introduction of adhesives at Singapore and Hong Kong.

The sender of a letter from the Philippines would know whether the ship carrying that letter was bound for Hong Kong or Singapore. He would affix the postage stamps current in that port. Note that in Singapore, Indian stamps were used until 1867, and then Straits Settlements stamps. Most letters from the Philippines to countries outside the Spanish empire up until 1877 do bear the adhesives of these British colonies.

Some business firms in Manila kept a stock of the adhesives valid at Singapore and Hong Kong. There is also a claim that the British Consulate in Manila held stocks of these adhesives.

The adhesives were not canceled until the letter was received by the Hong Kong or Singapore Post Office. Very few letters bear any Manila postal marking. Those that do, have a Manila date-stamp applied to the envelope, but not touching the adhesive.

Many of the letters bear a marking of a business firm in Manila. Sometimes this cachet indicates that a forwarding agent has handled this letter. More commonly it indicates the sender, just as we write our return address on envelopes today. Almost all letters originated in Manila. I know of only three covers from other locations.

In almost all cases the rate is the same as if the letter had been posted in Hong Kong or Singapore. The only exception is the Straits forwarding charge on mail going via Singapore in 1871-72.