Spread it round the garden is the usual answer. Being tight-fisted I often check it for bugs, especially vine weevils, add some slow release fertilizer granules and re-use it, but most people wouldn't recommend this.

I often reuse it - but adding fresh compost to the top half so that nutrients wash down into the old compost. Otherwise put spent compost in the garden.

First welcome to GOY Wulf and a Happy Christmas.

I empty my pots in my woodland area under my Mahonia and have fantastic compost

... and a big welcome from me too! I throw my old compost under the trees in the garden.

Mine goes on the compost heap

Thanks for all you replies, I'm sure the rest of my garden will appreciate it as well!

I do compost heap as well , I put in in layers, also top dress the borders

Gg

Following advice from the National Wildflower Centre at Liverpool - Wildflower seed needs to be sown in poor soil, as that is what they are used to. I collected old compost from friends as didnt have enough of my own.
Filled planters with it, and it was very successful.
It was wonderful to grow my own Harebells.
Planted out some of the others on a spare bit of ground on my allotment which proved too rich for them. They went silly and grew to the size of a card table. So that was the end of that bright idea. I am back to garden plants on that area of the allotment - it was the concrete under an old pig sty pen, the soil is only 6" deep.
Its best to use some kind of container, and use the old compost to provide the right growing conditions, but keeping them free of Couch Grass enables them to grow successfully. Also only sow one variety of seed !

According to Gardening Which? their study found that plants will do fine in old compost. But this might not be true of all plants as they obviously could not test all plants. If you are a member of Which? take a look at their website.