Two most widely known validation protocols are the one of Association for the Advancement of Medical Instrumentation (AAMI) and the protocol of British Hypertension Society (BHS). Both genuine protocols have been revised from the time of their first inception, and as the two can be reconciled, the joint criteria are applied in most published validation studies. The criteria for fulfillment of the BHS protocol are that the tested ABPM devices must achieve at least grade B for systolic and for diastolic pressures; the criteria for fulfillment of the AAMI protocol are that the test ABPM device must not differ from the mercury standard by a mean difference greater than 5 mmHg or standard deviation.

General overview shows that greatest number of validation studies have actually been conducted on ambulatory blood pressure monitors. For this reason, an evidence of independent validation should be available at purchase. Many of these devices have also been validated in special groups, such as among elderly and pregnant women, and in differing circumstances, such as during exercise and in various postures.

The Working Group on Blood Pressure Monitoring of the European Society of Hypertension (ESH) additionally published its International Standard and a list of recommended blood pressure monitors (British Medical Journal, year 2001). In the publication the standards and devices had been assessed on the published evidence of validation according to BHS and AAMI protocols. With a promise that the list of recommended ambulatory blood pressure monitors would be updated regularly, today this is still the most reliable guide for future buyers.