My son's baptism

[MyBreadIsEggy]

My newborn son will be baptised in the spring, my best friend also had a new baby who will be baptised. We both want each other to be our DS's God parents.
I'm Catholic and she is Church of England, so does anyone know if we would still be allowed to make the promises of godparents to a child of a different denomination?

Not a problem from the C of E point of view. Can't speak for the RC church.

In my experience (3DC) the RC church will require that one of the Godparents is also RC, the others being CofE isn't a problem. CofE will happily allow a RC Godparent.

The other 3 Godparents are baptised and confirmed RC - just my best friend who is CofE

In the RC Church, you can have either one godparent (who must be Catholic), or one man and one woman. In the latter case, one of the two must be Catholic and the other a Christian of any denomination, s/he is not technically a godparent but is called a 'Christian witness' although there's no pratical difference in what they say/do.

Some parishes will let you have more than two but it's technically not allowed. Check with your parish.

In practice, CofE are very very unlikely to object but it's still best to check.