upgrading to fibre 74

[#1]

So, you appear to be on the (very old) ADSL product, in which case your current router will not work with Full Fibre, and does need replacing.

[#2]

@Pete-21 

You didn't state which router you actually have. If you have a Hub1 it will work with Full Fibre but performance will tail off regarding speed from FF145 upwards.

Even if you have a Hub2 already getting a second one ensures you have a spare just in case.

Brian

[#3]

@bmc I  suspect the OP is on ADSL, with a non-fibre compliant router.