A strange letter requesting ESA1 form

Hi,

My partner has just received a letter from the Department of Communities, northern ireland. We live in northern ireland.

It reads;

In relation to your claim to Employment and Support Allowance.

We have received medical evidence for your claim but you have not submitted your ESA1 form in Northern Ireland via nidirect.gov.uk website.

For further information please contact 08001690310.

He is currently working full time for the same company gor about 15years, its a multinational HQ in the UK. He has always worked and thankfully has never had a need to claim any benefits. The national insurance number quoted is his and we checked all addresses etc and they are correct although the letter is riddled in typos.

Do you think this is a scam gone wrong? How could there be medical evidence when hes not sick and working full time? I would be very grateful if you could help with some questions for when he rings next week.

Thank you.