While it’s probable each local council will approach their paperwork differently, no matter your area, it’s likely you will be required to sign a contract and pay a fee
In our two cases, while arranged by the local council, the contracts were actually with the company handling the installation work, not the council. Each was a double-sided document of twelve clauses outlining what work was being done by the contractor, with an attached map and network diagram showing the house’s connection point. Because of this, it was important to know which manhole we would connect to and have any necessary supporting paperwork, before signing the contract.
At the time of signing, there was also a fee to be paid (itemised as part of the contract), covering a small contribution to the work done by the contractor, inspection of our connection when the work was complete – and, for one house, the cost of the manhole cover itself. (Yes, that’s right – the first owner connecting at a pit pays for the manhole cover, then the rest get it for free!)