O.C.G.A. § 34-9-221(d): Employer must controvert the right to compensation within 21 days. Failure to comply without reasonable grounds authorizes attorney fees. Raines &Milam v. Milam, 161 Ga. App. 860, 289 S.E.2d 785 (1982); See Carroll v. Dan River Mills, 169 Ga. App. 558, 313 S.E.2d 741 (1984)
Failure to controvert within 21 or 60 days even though benefits are started is not "statute of limitations" and you can still controvert. It does, however, open the door to attorney fees. See Cagle's Inc. v. Kitchens, 172 Ga. App. 698, 324 S.E.2d 550 (1984); But See Carpet Transport Inc. v. Pittman 187 Ga. App. 463, 370 S.E.2d 651 (1988)
Failure to make all proper payments prior to controvertion will prevent controverting a claim. See Southeastern Aluminum Recycling v. Rayburn, 172 Ga. App. 648, 324 S.E.2d 194 (1984)
O.C.G.A. § 34-9-221(h) and § 34-9-221(i).
If an employer voluntarily commits the payment of benefits but fails to put a statutory late payment, it cannot later file a notice to controvert of the entire claim. However this does not prevent the employer and their insurance company from filing a "notice to controvert" based on a change in condition. See Fallin v. Merritt Maintenance & Welding, Inc., 283 Ga. App. 485, 642 S.E.2d 122 (2007).
An employer's failure to pay all benefits currently due before filing a notice to controvert under O.C.G.A. § 34-9-221(h) renders that notice to controvert invalid. Southeastern Aluminum Recycling v. Rayburn, 172 Ga. App. 648, 324 S.E.2d 194 (1984). The court further cited Cartersville Ready Mix Co. v. Hamby, 224 Ga. App. 116, 479 S.E.2d 767 (1996) where they found that an employer had paid benefits but had failed to pay the statutory late payment penalty had filed an invalid notice to controvert and was therefore barred from contesting the claim on the grounds that the injury was non-compensable.