From memory, you currently have a 6 way fuse box?
Quote
Instalationl 10way populated consumer unit with SPD (surge protection consumer unit with 100A main switch and 2 100A 30ma RCD. ( https://www.screwfix.com/p/contactum-defender-1-0-18-module-10-way-populated-high-integrity-dual-rcd-consumer-unit-with-spd/829ha )
1/ Checks prior to installation of new consumer – Global Insulation Resistance of all circuits, CPC continuity of sockets and light circuits ZE, ZS and check for borrowed neutral.
If all ok proceed to install new consumer unit. If not discuss with customer any additional work or fault finding required and additional cost.
2/ Remove and Install new consumer Unit
3/ Post-installation testing – including insulation resistance, earth fault loop impedance and RCD functionality checks, verify the safety of a new consumer unit, fill out electrical installation certificate (EIC) and handover to customer.
Consumer unit £115
Labour £45 x 4- 6hrs = £270 max
EIC £110
Total £495 maximum