Travelling with visa in one passport and a new renewed passport

Hi there,
You have responded once to my email but the response contradicted itself. I have a passport valid until July 2017 with a business visa valid until June 2017. I will be renewing my passport in the UK in December. When I come back to Vietnam (flying into HCMC) in Jan (I live and work here) can I re enter with both passports? The British government passport office said I can keep both passports and just re enter on the visa in the old passport. My employer will then apply for my resident card to be put in my new passport.

Can you confirm that I can do this? Or do I need to get the visa transferred to re enter Vietnam?

Thank you