Probably a John Innes would be better - either strength 2 or 3.

thanks sue but I have to use what I can get and afford

You should be able to get John Innes at any garden centre and the fertilizer already in it should last quite a long time. In multi purpose you would need to start feeding much sooner. It is a compost designed for young plants or house plants. Trees and shrubs need something stronger and John Innes 3 is what is recommended. You should be able to get it and afford it without much problem. If you find you really can't afford it let me know -I think I have some in the shed.
How big is the pot?

Actually it is going to be a plastic dustbin which is why I can't use John innies because it is soil based and too heavy for me and Lyndon to lift. I have never fed my Peach but it still fruits fi we hand polinate it

Wow, how lovely to have home grown peaches!! Can you not put the dustbin in its final position before filling it? If the tree were in the ground you wouldn't be able to move it at all. Hope it has some drainage holes in the bottom. But if you can't use a soil based compost there would seem to be no alternative to multi purpose. What's it in now? Could you use a mixture of the two? I have done this before and know others have too.

I wonder why nobody else answered your question??