Has your husband been an 'employee' for tax purposes (i.e. paying tax under the PAYE system) or has he nominally been self-employed (sending in an annual tax return and paying his own income tax), as often happens with small concerns?
If he's never been an 'employee', then he's not entitled to any redundancy pay.
If he's been an employee, exactly who has his employer been? i.e. have his wages been paid by 'Joe Smith' or by 'Acme Ltd'? It's that employer who is responsible for paying his redundancy money (unless that employer is insolvent, in which case it's the National Insurance Fund which will have to pay out), so it's important to know whether it's an individual or a limited company that's due to pay out (as they're entirely separate legal entities and it's no good pursuing an individual company director for money if it's the limited company's duty to pay up).
This is a useful starting point:
https://www.gov.uk/redundant-your-rights/overview
Further advice is available from the ACAS helpline:
http://www.acas.org.uk/helpline
If your husband fails to get the money he's owed (other through the company's insolvency) he will need to send a formal demand for the money that he's owed, threatening legal action if he doesn't get it. If the employer still doesn't pay up, he'll need to go through the small claims procedure (which can be done online):
https://www.moneyclaim.gov.uk/web/mcol/welcome