Does anybody know about postal code history?

[agua]

Why are Ilford and Sutton the only post towns that have codes that don't match the actual titles (IG and SM respectively). Consider the other 10 codes:

EN - Enfield, KT - Kingston upon Thames, HA - Harrow, UB - Uxbridge, TW - Twickenham, CR - Croydon, DA - Dartford, BR - Bromley, RM - Romford.

I can somewhat understand SM as it covers both Sutton and Merton, but why I... G? The mind boggles.

[Bellringer]

When we were Teesside and post codes were introduced ours was TS. Now, we on the North of the Tees are back in County Durham we are still stuck with TS.

[brachiopod]

agua, I presume you mean "...of the Greater London Postcodes"?

Anyway, using your "Sutton & Merton" argument for SM, I could argue "Ilford & Gants Hill" for IG. Though somehow, I don't think either are correct.

Bellringer, although since this redrawing of boundaries, you are now in Co. Durham, your mail is still sorted in the same place - hence your postcode is still TS.
Your postcode has nothing whatsoever to do with geographical boundaries (boroughs, counties and the like) - but merely groups together areas served by the same main sorting office.
If you happen to live in Machynlleth, Powys in Mid western Wales - you will have a SY, or Shrewsbury postcode - and that's England!

The postcode is a tool for sorting mail - not to tell you where you live.

[agua]

brachiopod,
"Though somehow, I don't think either are correct."

Why not?
Although, I see your point. Our sorting centre is in Ilford, so where does Gants Hill fit into all this?

But if not "Gants Hill", what the heck does the G stand for?