Methods, systems, and devices for increasing physical random access channel (PRACH) capacity using orthogonal cover codes (OCCs) in wireless communications systems are described. A base station may transmit a PRACH configuration that indicates PRACH resources for system access, for example, in a system information block (SIB). A user equipment (UE) may receive the PRACH configuration, and may identify PRACH resources that support OCCs for system access. For example, PRACH configurations with small time domain spacing between PRACH resources may support OCCs. The UE may determine whether to transmit random access (RACH) preamble messages using OCCs in the PRACH resources, and may transmit a RACH preamble message to the base station based on the determination. In some cases, the base station may additionally indicate PRACH resources not configured for OCCs, and the UE may determine which set of resources to transmit in based on one or more parameters.