Incident reporting systems (IRS) allow providers, staff, and, in some cases, patients and families, to report healthcare errors or near misses. This systematic review contrasts barriers reported by providers and staff in the US and the UK. Providers in both countries cited fear of punitive response or retaliation, shame, and concerns about confidentiality as reasons for not submitting reports. UK providers more frequently identified concerns about damaging the professional culture within and between healthcare teams.