Mae'r gwariant yn cael ei fodloni gan Lywodraeth Cymru o Gronfa Gyfunol Cymru. Cafodd Etholiad y Senedd 2021 ei gyfuno ag Etholiad y Comisiynwyr Heddlu a Throseddu yng Nghymru. Costau etholiad y Senedd yn unig a gynrychiolir yn y data cyhoeddedig. Mae'r data yn cynnwys, ymhlith pethau eraill, costau llogi adeiladau, argraffu cardiau pleidleisio a phapurau pleidleisio a chostau staff. Mae hefyd yn cynnwys costau untro ychwanegol a ysgwyddwyd o ganlyniad i Covid-19, gan dystio i'r amgylchiadau digynsail y cynhaliwyd yr etholiad hwn oddi tanynt. Am yr un rheswm, gwnaeth y costau sy’n gysylltiedig â gwasanaethau a ddarperir gan weinyddwyr etholiadol barhau ar gyfer Etholiad y Senedd 2021. Bwriedir tynnu’r elfennau hyn ar gyfer Etholiad y Senedd 2026.
The expenditure is met by the Welsh Government from the Welsh Consolidated Fund. The 2021 Senedd elections were combined with the election of Police and Crime Commissioners in Wales. The published data reflects the costs of the Senedd elections only. The data includes, amongst other things, the costs of the hire of premises, printing poll cards and ballot papers and staff costs. It also includes additional one-off costs which were incurred as a result of Covid 19, reflecting the unprecedented circumstances under which these elections were held.  For the same reason, the costs relating to services rendered by electoral administrators remained for the 2021 Senedd elections. The intention is to remove these elements for the 2026 Senedd elections.