Note to all....
The first thing to know is that in UK law there is no need to have a written contract except for dealings in land - this is statuary and cannot be overidden by a Court, so a claim would not be thrown out just for having no written contract.
For a contract to exist in its simplest form there must be three items present:
An offer i.e I will rewire your house
An acceptance i.e. The customer says yes please rewire my house
An exchange of consideration ; I supply labour and materials and customer provides money
Presented like this a court would find a contract does exist.
Things get a little more complicated when there is disagreement over what was actually agreed, however in a domestic rewire situation this is not a particularly difficult exercise, the court would examine all the evidence and decide what a rewire means in that particular case bearing in mind the testimony of the parties/ industry norms etc
Any areas of ambiguity may be struck out but again the court may impose terms using any evidence presented
That said it is always best to have a written contract as this leaves no room for doubt as to the terms, any deviation/addition should also be in writing.
This may include, inter alia,
Overall price agreed
Day rate - and an estimate of the time to be taken (build in your problem jobs!!)
Materials to be used including Makes, Quantity etc
Access
Delays due to influnences out of your control - how to be managed and paid for
Finishes
Cleaning
Reinstatement of Furnishings, carpets etc
Delivery of test results /inform LABC
In to OP's post, there would be no difficulkty in showing a contract does indeed exist. He has done the work and has been partially paid - both sides openly admit having a contract, the problem is the nitty gritty - and this is for the court to decide.
If you do go to court go with 'clean hands', be honest,frank and open, do not bullsh1t. Judges hate liars and conners and have lots of discretion when deciding what the actual terms are - after all it is an opinion, based on the evidence available, not fact
This is not intended to be a full treatise on contract law in the UK and you are advised to seek qualified legal advice from your Solicitor in any action.
this is intended as a very brief outline for your information only
RegardsO)