On Sunday, 7 July 2019 12:30:54 UTC+1, T i m wrote:
She was sent a new 'key' and yesterday put £20 on it but when she put
it in the meter, got an error message:
'Your new key isn't talking to the meter correctly' ;-(
Like, if she got credit put on the key, would the shop get any
acknowledgement that it had worked correctly (eg, could they have seen
it f-up but taken her 20 quid anyway (she has the receipt))?

If she got the receipt then it worked.

If she took it to another place, could they tell her if it has any
credit on it or not (proving the key 'works' and there is credit on
it)?

Probably not.

How do Bulb get their money? Does the key determine that via the
payment terminal?

Yes.

I don't know that she followed (or saw) their online guide re using a
new key (in case it matters):

I think it may do.

Plug your Bulb key into the meter and wait for 60 seconds
This will register your key. Once thats done, well be your official
supplier of green electricity.
Top up at your nearest Paypoint, Payzone or Post Office"
So, are they saying there you *have* to 'register the key' (with the
meter presumably) *before* you add credit and try to use it,

I think so.

When I got a new key (they actually sent me to the shop with a reference number) I got the key which they updated on the payment terminal with the ref number, then I went home and keyed-in to the meter, then I took the key back to the shop and got some credit.

It might be worth (and probably won't do any harm) taking the key to the shop again and asking them to put it in the terminal, then back to the meter ....

She can also try Power Cuts on 105 and reporting loss of supply due to faulty meter. They might refer it back to the Bulb or they might come and legitimately bypass the meter to put her back on supply temporarily.

Owain