This will depend on the circumstances of the individual tenant. Some tenants may be working (approximately 40% of private rented housing benefit claimants are in work) and may be able to cover the rent through income from their job. Others may be able to get short term support from family or friends or use savings.
If a tenant is claiming housing benefit or universal credit, their benefit payment could change in response to a change in circumstances. Alternatively, if a tenant is not already claiming housing benefit or universal credit, and their circumstances change, then they may be eligible to apply for housing benefit or universal credit.