Britain moved one step closer to leaving the European Union on January 31 after the divorce deal bill was passed by MPs unamended.
The Withdrawal Agreement Bill passed 330 votes to 231, a majority of 99.
It now moves to the House of Lords - with peers unlikely to drastically alter the bill in the wake of Mr Johnson's convincing election win.
But Remainer peers are expected to table a wave of amendments - which would likely by undone by Tory MPs.
Brexiteers have already started planning the celebrations for the end of January.
Tory MP Kate Griffiths said a special Brexit pint should brewed to mark the occassion and former Tory minister Sir John Hayes called for the Union flag to be flown to mark Britain leaving the EU.
Speaking in the Commons, Sir John said: "That would be a fitting tribute to the decision the British people made to leave the European Union, and we will remain unafraid of our patriotism, unabashed about the departure, and unwavering in our determination to make our future even greater."
Although the UK's legal departure from the EU now looks inevitable, the battle over future trade terms is only just getting started.
The new EU Commission President Ursula von der Leyen came to London yesterday for her first face-to-face talks with Mr Johnson.
She said the UK would be "best of friends" but they will "not be as close as before" after Brexit.
But she warned it would be "impossible" to reach a comprehensive trade deal by the end of 2020.
She said if the deadline was not extended it was not a case of "all or nothing", but of priorities.
