There are two dimensions to this question.
One is technical: there is a set of rules which apply to parties and party members. These are not quite the same as the rules for independent candidates, and you’ll need to learn your way around them. I’ll come to that in a moment.
The other is personal: if you join a party, what are you signing up to? Is it a shared manifesto, a set of policies or principles, or something else which all party members hold in common?
Whatever it is, it is likely to have some effect on what you choose to include in your campaign. Depending on how your party is structured, it may have some rules about what you must say, and perhaps also what you cannot say.
There might be internal rules about vetting manifestos, or providing consistent answers to questions from voters. All that depends on what you agreed to when you signed up to the party.
But if there are more constraints, there might also be more freedom. If, for example, you know that there is going to be a central party manifesto which deals with a number of key issues, perhaps that frees up more space for you to concentrate on the issues that matter most to you, in your own manifesto.
Parties might bring new campaigning opportunities, as well – parties might, for example, organise their own “meet the candidate” events or hustings, which might draw a different crowd of voters to those you would reach on your own. All of this is stuff you need to discuss within your party, so that each of you can decide how best to run your own campaign.
On the technical side, the spending rules are slightly different if you are in a party. Again, the official candidates’ guide is your best reference for this. Essentially, your party has no spending rights unless you, as its members, choose to give it some. You can transfer part of your own spending allowance – this means you will spend less, and the party can spend what you have allocated to it. That’s added together with transfers from other party members to make the party’s total spending limit, which is an absolute maximum of £9,000. You don’t have to transfer actual money to the party, just the right to spend it.
There are specific rules about parties, and how they should be registered, and how they should conduct themselves. Your party officers need to learn their way around those rules; I won’t be unpacking them here. (A party structure is supposed to provide some of the support that independents don’t have, so I’m not going to duplicate its work!)
For individual party members, it’s just worth remembering that any financial support you receive from the party still needs to be consistent with the Election spending rules, and that you are still responsible for recording and submitting your own election expenses, whether or not you are a party member.
Finally, when you submit your nomination form, you will be asked to declare if you are affiliated to a party, and to give the name of a party if so. There is also space on the States manifesto template (see pages 42-46 of the guide) to include a party logo if you want to. So if you’re thinking of joining a party, you’ll want to have made a decision before the nomination period opens!