This is a useful chart from the HPA, which I’m linking to here so that I can reference it at work if needed.
Another useful point (from the BMJ learning module on immunisations, which is where I got this) is that conjugate vaccines (Hib, Men C and pneumococcus) produce a better immune response after one year than they do before. It’s still far better to give them to babies on the normal schedule, as otherwise babies remain unprotected and vulnerable to these infections for their first year (and also able to transmit them to others), but if a child hasn’t had those particular vaccines on time and doesn’t get one or other of them until over a year old, one dose is enough without boosters being needed. (At least, that was my understanding of the module. I’m meaning this as an aide-memoire to myself, not official advice, and if you are involved in arranging vaccines for an unvaccinated/partly vaccinated person then CHECK the schedule.)