I have a Main service I am replacing in California, I want to use QO breakers so I will have to have a made up configuration, only used all-in-ones in the past. So the meter socket, then nipple into hub on top of 3r main panel, but do I need a bonding bushing and a egc. from neutral connection in meter socket to panel or just the three service conductors, neutral bonding to center clamp or buss.? It's just a SFD 125amp service. 817 sq. ft home.

Yes on bonding the nipple if it is metal. You pull in the service neutral and the ungrounded conductors.
If the PoCo grounds the neutral, you can usually get a fist fight started about using a metal nipple because that becomes a parallel neutral in some people's mind when you put in the MBJ.
OTOH 250.24(A)(5) really only applies on the load side of the service disconnect.
It is a question to ask your AHJ to see how he reads it.

Two POCOs here have different outlook on this.

One allows nothing within the meter cabinet except the line and load neutrals and hots. The other one is OK with the GEC bonded to the neutral within the meter cabinet.

Greg hit it right with speaking to the local AHJ for his take.

We have the same thing here but it is the AHJ who has the opinion. Down in the county south of me, the GEG usually lands in the meter can. Up here they want it in the service disconnect enclosure although the code allows it either way.

The other issue I addressed is whether it is a problem that the neutral in the meter can is bonded to the can there and again with the main bonding jumper in the service disconnect enclosure. About half of the inspectors say this means you need a plastic nipple between them to avoid current between the enclosures, the rest do not see it as a problem.
I suppose you could cite 250.6
OTOH if you have multiple service disconnects on one service you are required to bond the neutral in each one so you have set up the same type of situation.

OK, I'll 'fess up how I found out.
My full time town is the utility that allowsnothingin the meter,my PT town allows it. I called an EC from the PT town to say'why', and he told me it's OK with the POCO. I gave him a 'pass'.

I later checked the POCO website & it's in their layout.

Live & learn.

John,

I get that all the time in my town with bonding of neutral/ground or not. Some of the JC's people will allow grounding in meter pan and some won't.

The argument I have heard against landing the GEC in the meter pan is it may not be accessible.
Some areas around here have enough power theft that when they seal a meter you are not getting in it without a special key.
It is not just the wire seal, it is a locking band.

So my supplier got me a UGOH meter socket that is convertible to main breaker. Sq D C125RB that has a left section for Opt. breaker, I had asked for a 125amp meter. Since this has means for terminations, do I have to bring GEC into it and not terminate GEC in Main panel? Or do I just pickup a Milbank meter socket at Home Desperate. My Sq D supplier Could only get 100amp or 200 amp sockets stand alone? I need 115 amps for total with 40 amps solar back feed. So he got me this 125amp Sq. D with side feed compartment? I cannot find from the Schneider site line and load termination points. I assume the left section is for UG feed, but it is also convertible.

The SqD web site is being cranky and it won't let me download the instructions for that particular meter main but generally your GEC would land on the load side bus in the compartment with the service disconnect where the main bonding jumper is.
The service conductors land in the "line" side where the meter socket is. There are jumpers in between.

Thanks greg, So if I have the main breaker in the dist. panel, and even though the meter cabinet is convertible I don't have to treat as main, even though it does have provisions....I can just makeup as a load out of meter cabinet to main breaker for qo1624l125grb panel. I think the left side is for under ground feed, but cannot get info from website, and have no experience with this type of cabinet.

I guess my question is is there any benefit to using this convertible type over just the standard box. The question is is that left section for breaker and load out, or for underground feed, and the main breaker is optional elsewhere? cannot tell from the cut sheet where the bussing goes.

I am not sure why you would buy a $300 meter/main and not put the main in there.
If you are using a service disconnect somewhere else buy the $30 meter can. There is no problem using a 200 a meter socket on 125a service.