Redundancy pay
He should check how much statutory redundancy pay he is entitled to. This will depend on his age as well as how long he has worked there.
www.gov.uk/calculate-your-redundancy-pay
He should also check his contract to see if he is entitled to contractual redundancy pay.
Contribution-based benefits
He should be entitled to 'new style' JSA regardless of what other income or savings he has. He just needs to have paid enough NI over the past couple of years. Usually there is a requirement to look for work and be available for work but this has been suspended until at least 29/06/20.
He can claim 'new style' JSA either on its own or together with means tested benefits.
Means tested benefits
It's not clear whether he is currently getting working tax credit, child tax credit or both. Sometimes people think they get child tax credit because they get help towards childcare but this is actually part of working tax credit. It is possible for one person to claim child benefit and another to claim child tax credit for the same child but I'm not sure how common this is or how many headaches it causes.
He needs to tell HMRC if he is made redundant and he will lose any working tax credit he is currently getting. If he gets child tax credit the amount should go up because he is on a lower income.
He will need to find out whether he would be better off staying on tax credits or moving over to universal credit and he should find out before he loses his job.
This is because if he is just getting working tax credit he can add child tax credit to his claim. If he loses his job and so loses working tax credit he cannot then make a new claim for child tax credit, he would have to apply for UC instead.
Similarly, if he later gets a job but is on a low wage or needs help with childcare, he will only be able to make a new working tax credit claim if he is already getting child tax credit.
Turn2Us benefit calculator is quite good but should not be treated as gospel:
benefits-calculator.turn2us.org.uk/AboutYou
Does he have savings? Savings are disregarded for tax credits but UC assumes an amount of income from any savings over £6K and if he has over £16K he would not be entitled to any UC at all.
Redundancy pay is treated differently under UC and the old benefit system. Statutory redundancy pay is not taxed and will not affect any tax credit claim. Contractual redundancy pay is taxed over £30K and so may affect his tax credits.
Both statutory and contractual redundancy pay are treated as capital for universal credit claims.
The benefit system does not provide much support for mortgage payments. There's a loan you can apply for after 9 months on UC but it only pays the mortgage interest and the loan itself is not interest free. This is not available if he stays on tax credits. He should check with his mortgage provider whether he can get a 3 month payment holiday and what the terms are. He should also check the terms of his mortgage payment insurance.
He should also check with his local council if he is entitled to Council Tax Reduction, whether or not he claims other means tested benefits.