Under domestic EPC legislation non-compliance will result in a fine of £200.
Your current tenancy agreement may be deemed invalid or your house sale fails to finalise.
Commercial EPC legislation non-compliance will result in a penalty. The indications are that this may be based on 12.5% of the rateable value of the property in question, with a minimum of £500 and maximum of £5,000.
The penalty is £500 for failing to display a DEC at all times in a prominent place clearly visible to the public and £1000 for failing to have possession of a valid advisory report. The DEC is valid for one year.