David and Sharon Purvis sold fake Smirnoff and Glen's vodka at the Black & Gold pub in Shielfield Park, Tweedmouth.
The pair pleaded guilty to offences under the Food Safety Act 1990 at Berwick Magistrates' Court.
David was fined £440 and ordered to pay a victim surcharge of £44. Purvis was fined £150 and ordered to pay a victim surcharge of £30.
They were each ordered to pay legal costs of £250 and investigation costs of £1,274 totalling £3,712.
Trading Standards officers found a number of bottles were below the ABV strengths their labels declared and were made from industrial alcohol rather than agricultural, during a visit in August 2017.
The court heard a member of staff accepted the bottles from a relative who had them as unwanted gifts.
Councillor John Riddle, cabinet member for planning, housing and resilience at Northumberland County Council said the pub was playing roulette with its customers’ health.
He said: “Alcohol of this type is usually bought cheaply from itinerant traders who are not legitimate suppliers.
“Our Trading Standards team has found quantities of fake vodka and whisky at pubs and small retailers across the county.
“A business that sells this type of alcohol plays roulette with the health and wellbeing of its customers and we will not hesitate to prosecute or review the licence to sell alcohol where we feel it is appropriate.”
David Sayer, business compliance and public safety unit manager at Northumberland County Council said legitimate wholesalers needed approval by HMRC.
He explained: “You really don’t know what you are getting if you are buying from any other unknown source.
“Our officers inspect business premises regularly and an investigation will be conducted if a business is found to be supplying any type of illicit alcohol like the vodka found in this case.”