Cell phone purchase price business deduction

I am seeing mixed answers on this subject. I purchased a phone that I use for both personal and business needs. I calculated the percent usage to be 30% for business (1099 sole proprietor) and 70% personal/W2 job usage. I paid for the phone as a lump sum in 2019. I already plan on deducting 30% of the price of the phone bill. Am I able to deduct 30% of the phone purchase price as well? This is where I am seeing mixed answers, some saying no based on a ">50% business use rule" or something like that. Thank you in advance.