How to onboard a new employee in the UK?

Onboarding Steps

1. Send the employee an offer letter confirming their job title, proposed start date & salary. Do not send a contract immediately after deciding to hire someone. If you send & sign a contract and then you find out that someone left their last employment due to misconduct or worse, you will be contractually obliged to pay that person for their notice period even if they haven't yet joined this company. Most people skip the above step until they encounter this. It is rare but it happens. The offer letter should state that the employment offer is conditional on reference checks, criminal background checks, right to work checks & other internal checks.
2. After the employee has received their offer letter, ask them to i) share their references with you, ii) complete a DBS check using a platform like uCheck/HR-Platform and iii) share a copy of their passport & proof of address to enable you to do a Right to Work & DBS check. When asking for the new hire to do this, it is worth confirming in writing that they consent that you use the data they share to do a DBS check (passport photo & proof of address phone/utility/bank statement). Again, this is annoying, but without this you risk hiring someone & then finding out that they have a criminal record.
3. Doing References: It is worth trying to do references but many big companies will have policies against them and may only confirm someone's job title & dates of employment. If someone does find time to speak to you and they give you a lukewarm reference, this is not a good sign. It is probably too late to change course, but it is worth noting for the future & you should try to support the new joiner more than usual to help them to succeed in your workplace.
4. Right to Work Checks: Seeing a UK passport is a good proof of right to work, but for anyone from the EU, or on a visa, you will need to do right to work checks. If this is the case, ask them to share a Right to Work code with you. The new joiner is able to generate the Right to Work code here. You will then need to check their code & documents, inputting the result here.
5. Send contract: Once you're satisfied with the references, send your employment contract to the employee for signing, ask them to fill in a New Joiner Form and share their P45 from their last job. If they don't have a P45, ask them to complete this form here.