UK Landlord Forum / Life

I have had tenants now for the last six months, with agreement for six months, which was due to be renewed yesterday. I haven't done so and am thinking periodic until I sort stuff out with them.
To be honest am not sure where I stand. I have had rent paid late due to them being on holiday, bank made mistake, new wage system at work. Rent short paid due to lost time sheets. Rent paid in bits. Last one has been no rent at all for September month due to company going bankrupt. Tenant now tells me he has a new job and would be able to pay October on time. I asked him how he proposed to pay the other short payments, and indeed no payment. He replied he planned to pay extra every month, starting next month until arrears were clear. On date of rent due he again didn't pay stating that 'if I was thinking of evicting him' he did not want to pay me. I explained to him that I had not suggested that, and was merely asking for a payment plan in place. Now I check my bank to find he has short paid me again. Private tenant not DHSS, private agreement, though official as in from Government website. Though as I said no contract now in place.
Advice gratefully received. Can't 'pop round' as out of country.

Please does anyone have any thoughts on this one.
I am about to write to tenant today regarding the payments, and explain that I will not be renewing the contract. Is there anything else I can put in place to make sure they leave basically?
Tenant appears to be sweetness and light when I agree or sort stuff for them, however slightest show of me being unhappy with a situation and he turns. Am actually worried about sending my relative to check the property, does it have to be her alone or can I insist that someone else accompanies her?

Serve a sec21 take the hit and move on