Trimphone model range

Throughout its production run the Trimphone had a large number of different models and variations.

All GPO phones had model numbers normally stamped on the base of the phone, and as long as the numbers are still readable you can work out which model it is.

Trimphone 1/722L MOD 1969 with lettered dial

Original dial Trimphone (1964 to 1982)

The Trimphone went through several revisions before the final version, the 2/722, was offered in 1971. Trimphone model numbers were:

The early Trimphones were supplied with lettered dials and these were shown on the Post Office's first publicity leaflet for the Trimphone. These are very rare.

All Trimphone dials had a transparent fingerplate over the numbers. Those on the 712 are subtly different and cannot be interchanged with the later 722 models.

The letters L and F after the model number indicate a lettered (L) or figured (F) dial. So Telephone 1/722L is a lettered dial version of the 1/722. The vast majority of phones for sale on eBay are of the 2/722 type with a figure dial.

The field trial phones can be identified by additional numbers on the base. To read more about the field trial phones, how to identify them and what the extra number on the base mean see: Field Trial Trimphone

Push button phones 1975 to 1982

Also look out for a special version of the Push Button Trimphone introduced to celebrate HM the Queen's Silver Jubilee. This was not the only Silver Jubilee phone; the GPO also did a special version of the Compact Telephone 776.

PST (modern socket) phone 1982

Deltephone Deluxe

Courtesy of BT Heritage

Deltaphone - 1980

The Deltaphone was part of the GPO/BT's special range. They were more individual style phones. Subscribers had to pay significantly more to rent the special range, which included some antique style phones, some modern style designer phones and a Mickey Mouse phone.

The Deltaphone, which was STC's original name for the Trimphone, was a white Trimphone clad in leather. The Deltaphone only came in brown leather. The Deltaphone De-Luxe was a keypad version. You could get the Deltaphone De-Luxe in red or green leather.

Phoenixphone (Snowdon Collection)

The Phoenixphone was available as a dial Trimphone (8722) or a push-button one (8766) in a range of new colours: two-tone red, olive green/beige, two-tone orange, black/grey, light green/mid green and cream/brown.

By Steven Braggs, April 2014

Your comments


May I update your leather Trimphone info. The one you picture was actually id'd as SR 1016A, and as you say,was produced in both red and green leather. The dial version was SR 1006. All my versions are dated 80/1 or 81/1.

DaveW" Dave Whistler 28/05/2019


Is their any other way of finding out the age/model of a trim phone when the stamp/information given as above has worn off. We can still see part of one of the stamps which looks like a white circle with first line letters PO.
Thank you in advance for any help
Regards" Mia 17/05/2020

"Hi Mia,

Yes. But, you will need to take it apart. The components were mostly stamped with the same style date information. You have to be careful though as these phones were sent back the GPO and refurbished. So older phones might end up with parts from newer phones." Steven 17/05/2020

To prevent automated Bots from spamming, please enter the text you see in the image below in the appropriate input box. Your comment will only be submitted if the strings match. Please ensure that your browser supports and accepts cookies, or your comment cannot be verified correctly.
Retrowow - vintage, retro and social history
Retrowow - vintage, retro and social history