Document and Entity Information - USD ($)		12 Months Ended
	Apr. 10, 2020	Dec. 31, 2019	Jun. 30, 2019
Details
Registrant CIK		0001092570
Fiscal Year End		--12-31
Document Type		10-K
Document Annual Report		true
Document Period End Date		Dec. 31, 2019
Document Transition Report		false
Entity File Number		000-27031
Entity Registrant Name		FULLNET COMMUNICATIONS INC
Entity Incorporation, State or Country Code		OK
Entity Tax Identification Number		73-1473361
Entity Address, Address Line One		201 Robert S. Kerr Avenue, Suite 210
Entity Address, City or Town		Oklahoma City
Entity Address, State or Province		OK
Entity Address, Postal Zip Code		73102
Entity Address, Address Description		Address of principal executive offices
City Area Code		405
Local Phone Number		236-8200
Phone Fax Number Description		Registrant’s telephone number
Entity Well-known Seasoned Issuer		No
Entity Voluntary Filers		No
Entity Current Reporting Status		Yes
Entity Interactive Data Current		Yes
Entity Filer Category		Non-accelerated Filer
Entity Small Business		true
Entity Emerging Growth Company		false
Entity Shell Company		false
Entity Public Float			$ 198,822
Entity Common Stock, Shares Outstanding	14,539,675
Entity Listing, Par Value Per Share	$ 0.00001
Amendment Flag		false
Document Fiscal Year Focus		2019
Document Fiscal Period Focus		FY