A careful examination of the fundamentals of electromagnetic theory shows that due to the underlying mathematical assumptions required for Stokes' Theorem, global charge conservation cannot be guaranteed in topologically non-trivial spacetimes. However, in order to break the charge conservation mechanism we must also allow the electromagnetic excitation fields D, H to possess a gauge freedom, just as the electromagnetic scalar and vector potentials ϕ and A do. This has implications for the treatment of electromagnetism in spacetimes where black holes both form and then evaporate, as well as extending the possibilities for treating vacuum polarisation. Using this gauge freedom of D, H we also propose an alternative to the accepted notion that a charge passing through a wormhole necessarily leads to an additional (effective) charge on the wormhole's mouth. * https://orcid.org/0000-0003-1597-6084; j.gratus@lancaster.ac.uk † https://orcid.org/0000-0001-5744-8146; Dr.Paul.Kinsler@physics.org ‡ https://orcid.org/0000-0003-0643-7169; m.mccall@imperial.ac.uk arXiv:1904.04103v1 [gr-qc] 8 Apr 2019 III IV L i g h t c o n e J f = 0 J b = 0 J f = 0 J b = 0 J f = 0 J b = 0 J f = 0 J b = 0 J b = 0 J f = 0 FIG. 5: Domains in a spacetime M where J f (blue) and J b (red) may be non-zero; note in particular that the supports of J f and J b do not intersect. For completeness, we show several different regions where the various possible combinations of zero and non-zero J f and J b hold, although alternative (and simpler) scenarios are possible. Note that Region I matches the cone shown on fig. 4, and Region IV encompasses both a section above the light line, as well as below.