mtDNA Haplogroup Hierarchy Finder supports batch search. User may submit a data file containing multiple mtDNA samples separated by comma. Each sample takes one column and filled with SNP positions. Here's the template in CSV format for user's mtDNA data.

The result file can be downloaded, in CSV (comma separated value) format, also contains multiple samples taking two columns for each sample. The first column lists the SNP positions and the second column lists the matched group info for the specific SNP position. Note that a SNP position may result in multiple group info, each group info will be shown in the separated row.

At this point the mitochondrial haplogroup is sourced from PhyloTree_mt's mtDNA tree Build 17 (18 Feb 2016) release. Refer to https://www.phylotree.org.