He was adamant he didn't receive the first dose of Moderna and wants to complete the Pfizer series; Patient received the first dose of Moderna on 07-Apr-2021 and dose two of Pfizer on 23-Oct-2021.; Patient received one dose of Moderna and other dose of Pfizer; Patient received one dose of Moderna and other dose of Pfizer; No Adverse Event; This spontaneous case was reported by a pharmacist and describes the occurrence of CIRCUMSTANCE OR INFORMATION CAPABLE OF LEADING TO MEDICATION ERROR (He was adamant he didn't receive the first dose of Moderna and wants to complete the Pfizer series), INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Patient received the first dose of Moderna on 07-Apr-2021 and dose two of Pfizer on 23-Oct-2021.), INTERCHANGE OF VACCINE PRODUCTS (Patient received one dose of Moderna and other dose of Pfizer), COVID-19 IMMUNISATION (Patient received one dose of Moderna and other dose of Pfizer) and NO ADVERSE EVENT (No Adverse Event) in a 44-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 021B21A) for COVID-19 prophylaxis.    Co-suspect product included non-company product TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) for COVID-19 prophylaxis.    No Medical History information was reported.   On 07-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 23-Oct-2021, the patient received first dose of TOZINAMERAN (PFIZER BIONTECH COVID-19 VACCINE) (unknown route) 1 dosage form. On an unknown date, the patient experienced CIRCUMSTANCE OR INFORMATION CAPABLE OF LEADING TO MEDICATION ERROR (He was adamant he didn't receive the first dose of Moderna and wants to complete the Pfizer series), INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Patient received the first dose of Moderna on 07-Apr-2021 and dose two of Pfizer on 23-Oct-2021.), INTERCHANGE OF VACCINE PRODUCTS (Patient received one dose of Moderna and other dose of Pfizer), COVID-19 IMMUNISATION (Patient received one dose of Moderna and other dose of Pfizer) and NO ADVERSE EVENT (No Adverse Event). At the time of the report, CIRCUMSTANCE OR INFORMATION CAPABLE OF LEADING TO MEDICATION ERROR (He was adamant he didn't receive the first dose of Moderna and wants to complete the Pfizer series), INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (Patient received the first dose of Moderna on 07-Apr-2021 and dose two of Pfizer on 23-Oct-2021.), INTERCHANGE OF VACCINE PRODUCTS (Patient received one dose of Moderna and other dose of Pfizer), COVID-19 IMMUNISATION (Patient received one dose of Moderna and other dose of Pfizer) and NO ADVERSE EVENT (No Adverse Event) outcome was unknown.        The action taken with mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown) was unknown.   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   No concomitant medication details were provided. No treatment medication details were provided.  The patient was there to get the second dose of the Pfizer covid 19 vaccine and it looks like the patient received a Moderna covid vaccine back in April. The patient declines that they did not receive the Moderna covid vaccine.  The pharmacist was inquiring of they should give the second dose today or not. The patient made the appointment online to receive the Moderna vaccine and the charts are showing that the patient received it. The patient doesn't remember getting the Moderna covid vaccine declined that he got it. The caller told the pharmacy that he never had any previous covid vaccines, so they gave him his first Pfizer covid vaccine. Now the patient was back to get the second dose of the Pfizer covid vaccine, but the pharmacy was showing that he had already received 2 total doses of the covid vaccines- one Moderna, one Pfizer.  This case was identified as part of a retrospective clean-up activity where certain emails received in the Moderna mailbox were missed to be booked-in.