Marriage for VISA

Hi there, I have been with my gf for 2 years she is from Hunan. We are planning to get married in July then apply quickly for VISA to UK (because my work is here and we tried living in China together first).
Once I get the marriage certificate, will i be able to use that for the visa? or do I need to wait till I get back to the UK and inform the local government to make it valid?
many thanks