Breach of lease delivery

Hi Everyone

I'm managing my own IP and the tenant did not pay last fortnights rent, I've tried calling and left a message but no reply so I'm going to issue a breach of lease.

I also got an over due water bill about a month ago, called the tenant and they said they would pay it straight away but I just got a new letter today saying it's still over due and legal action would be taken if it's not paid is 7 days so I want to issue a breach for this as well.

What's the best way to issue these notices? If I deliver by hand can the tenant just say they never got it to drag the process out? Should I use a bailiff?

If they don't cooperate and pay the rent and water I want to get them out as quickly as possible so don't want to give they opportunity to drag out the process..

Thanks

Michael

Breach of lease delivery