Caiff busnesau sy'n gwerthu nwyddau'n uniongyrchol i'r cwsmeriaid sy'n eu defnyddio eu diffinio fel manwerthwyr. Yr ystadegyn allweddol ar gyfer manwerthu yw'r Mynegai Gwerthiannau Manwerthu (RSI), a gyhoeddir yn fisol. Mae data yn y RSI yn ymdrin â gwariant ar nwyddau yn unig (mewn siopau ac ar-lein). Mae data am wario ar wasanaethau ar gael ym Mynegai Gwasanaethau (IoS).
In January 2018, the underlying pattern in retail sales, as suggested by the three-month on three-month measure, is one of slow growth with the quantity bought increasing by 0.1%; the lowest growth since April 2017.
The monthly growth rate for the quantity bought increased by 0.1% with declines across all main sectors except non-food stores.
When compared with January 2017, the quantity bought in January 2018 increased by 1.6%; a slowdown to year-on-year growth when compared with an increase of 2.4% in January 2017.