Its  my understanding that clan gold stays with you in your account once collected

But not 100% certain as I personally have  not left my clan since this was implemented  into the game

I'm certain that you keep the clan gold.  My daughter's clan disintegrated over the quests and when she left and joined a new clan, she still had the gold she had earned.

I've tested this, you keep your clan gold. My clan allows anyone who wants to,  to  go to our baby clans to do the quests and come back. 

thank you, I understand !

Hello! So from what I understood, do we need the permission of the guild to leave with the clan gold? 

you do not. you always keep clan gold when leaving your clan.

the clan coins you earn are personal rewards and have nothing to do with the rest of ur clan as everyone earns their own coins individually, and im certain as others said above you will keep them when you rejoin a new clan, you dont need to ask permission, they are ur coins and ur free to leave and join any clan when you want.

One of the actual great things RAID has  in the game is the 100,000 s  of clans  in this game

kind  of  goes  in hand with the millions  of players who play the game daily .................but to my point

leave and  join any number of times you want to clans  until you find the right fit for your gameplay style

all the clan gold you aquire along the way transfers with you to the  next clan to spend in their clan shop as you wish :)

Sometimes its  good just to hang in a inactive clan to get good pick of clan quests to complete and get the pts needed to spend  in the shop / then once a stockpile  is  built  up find a good clan fvor your needs :)