Great Britain 1d Inland Revenue - Postal Or Fiscal Usage?

This is the 1881 1d Inland Revenue stamp with orb watermark.

I was ready to add this to the revenue/fiscals stockbook but I noted the cancel was (I think) a postal-type oval registry cancel for Gresham House (EC2, London). That is indeed in blue; first time for me to see an oval registry cancel struck in blue.

So is this postal usage or fiscal? I know high values were used to pay for both charges and 1d on a registered cover might be from that kind of usage. And does a blue oval registry cancel have some meaning?

It is not unheard of for revenues to sneak through the regular mail system. I am sure some of the revenue experts can weigh in on this.

from 1881 postal and fiscal stamps were unified. The stamp you post is one of those that could be used to prepay for carriage of mail. Basic registration fees started at 2d.

There is very little reason to suspect it is anything but what it looks like: a postally used fiscal stamp used on a registered item.

A search of Gresham House Registered on eBay is revealing!

Thank you NSK for the education!

Gresham House was a Post Office (Branch Office)

Registered hammer unlisted in database.

Thanks to NSK and all for their input.