Is this OK?

[Podooser]

An upstairs spur double socket from a downstairs ring.

 

[RF Lighting]

It's not good practice, but could be done as a last resort as long as it is clearly labled (so if someone turns off the upstairs ring to make some alterations they realise that your socket will remain live)

 

[delmel]

An upstairs spur double socket from a downstairs ring.

It could be done and i have seen many houses wired in that way, half house one ring, half on another, not a method of my choice.

 

[reggie perrin]

I've come across three sockets in a kitchen from three different circuits.

Upstairs, downstairs and a radial.

 

[Paul Barker]

Working in a bungalo right now where original builder joined both rings so two breakers to everything. No evidence of alterations and judging by fact I found a joist sat on and squashing a cable, looks like he got it wrong in the first fix even before the joiners had been.

 

[Steve3948]

An upstairs spur double socket from a downstairs ring.

It could be done and i have seen many houses wired in that way, half house one ring, half on another, not a method of my choice.

It's the way I do it, spreads the load across rings, keeps cable lengths equal.
Kitchen and bedrooms above on one ring, rest of house on another.
If wiring a big house it makes sense to only go to each area of the house with a ring covering up and down at the same time.