There is one basic rule. It is that uncertainty must be reported unless there is an accepted Metrological equivalent. In the U.S. the equivalent is the 4:1 rules, specified in ANSI/NCSL Z540-1-1994, section 10.2.b. A U.S. based calibration lab can avoid reporting specific uncertainties IF a 4:1 can be maintained for the affected calibration area, AND the lab can put the evidence on the table for the accrediting body.
In the Phillipines, I do not know if the 4:1 or a similar rule is recognized. If no Metrological equivalent is recognized formally in the Phillipines, then you must report uncertainty.
Hope this helps.
Hershal