"Ethnicity" testing is mostly a gimmick. It is not as refined or precise as most people seem to think. The genetic differences between most European populations are relatively small. All that a DNA test can say regarding "ethnicity" is that some percentage of your DNA resembles a reference sample of people from a given location with all four grandparents born in that location.
My results from various testing companies:
23andMe: 76% British and Irish, 8.7% French & German, 5.6% Scandinavian, 0.8% Italian, 8.8% broadly NW European, 0.1% broadly Southern European.
Ancestry: 62% England, Wales & NW Europe, 32% Ireland & Scotland, 4% Germanic Europe, 2% France.
(Note: I also have 43 "DNA circles" for known ancestors and four "genetic communities" that match the origins or known migration patterns of ancestors on Ancestry).
LivingDNA: 79% Britain & Ireland, 21% Germanic.
FTDNA (Ancestry upload): 78% British Isles, <2% Eastern Europe, <2% Finland, <2% Southeast Europe, 3% Iberia, 10% West and Central Europe.
MyHeritage (Ancestry upload): 81.4% English, 15.3% Scottish, Irish & Welsh, 3.3% Iberian.
As you can see, there's an awful lot of variation between those; the only thing they agree on is that most of my ancestry is from the British Isles (which is accurate, based on my paper trail and DNA matches).
The ethnicity results are vaguely interesting, but DNA testing is something best used in conjunction with traditional genealogy, where it can verify relationships (or disprove them) going back for around 5 generations (to third great-grandparents) in most cases and as far back as 10 or 11 generations in some cases.