UK Landlord Forum / Life

Hi...Our tenant has defaulted on his rent. He has been flakey for a few months and we have tried to help him, but now he has blocked our number so we have no option to start the eviction process.  In addition we have  been informed that he has broken the no Pet clause of his contract. We wish to commence proceedings to recover his unpaid rent and are looking to evict him. He rented the property after 2015 so am I right in saying it's section 8 we need to start the proceedings? Does the 3 month 'grace' period still apply even though he had broken his contract? Thank you.