British MEPs have been given details of transition payments that could see the longest-serving eligible for six-figure sums, as well as instructions on clearing their offices before Brexit day.

The UK’s 73 members of the European parliament received confirmation on Tuesday that those under pensionable age would be entitled to claim the allowance after 29 March 2019.

All MEPs are entitled to a transition allowance linked to their length of service in the parliament to bridge their move into a new job. MEPs who have served one term could get a maximum pre-tax payment of €50,900 (£44,930), while an MEP in office since 1999 could receive €169,680 before tax.

MEPs at the EU retirement age of 63 are not entitled to the transition payment, as they move straight on to pensions. MEPs are expected to inform the parliament and give up the transition payments once they have new jobs.

One parliament source described the discussion as “a technical, logistical meeting... not a noses-in-troughs meeting”. It was attended by 30 to 40 MEPs from across the UK political spectrum.

With 157 days to go until Brexit, MEPs were told they had to clear their offices in Brussels and Strasbourg before 29 March, and hand in their EU passes, voting cards and any parliament laptops and iPads. British MEPs are leaving the parliament nearly three months before the official end of their mandate in June because Brexit day falls before European elections between 23 and 26 May 2019.

British MEPs’ assistants in Brussels will receive the equivalent of one month’s salary and a resettlement allowance. To help to wind down their work, British MEPs will get a reduced office allowance of €6,624 between April and June. The EU will pay for up to 15 boxes of office equipment to be shipped back to the UK.

MEPs and their assistants will also be able to make use of a European parliament helpdesk to smooth their departure.

The pro-remain MEP Julie Girling, expelled from the Tories after clashing with the leadership over Brexit, tweeted that she had “never seen so many Ukip members attend a meeting in Strasbourg before”.

The majority of Ukip MEPs, however, have attended at least 70% of European parliament votes, not far off the average of Labour and Conservative MEPs, according to VoteWatch Europe data on the 2014-19 session shared with the Guardian.

The Ukip voting average is brought down by the party’s former leaders Nigel Farage and Paul Nuttall. Farage has attended 40% of roll-call votes, the worst voting record of all British MEPs at the European parliament, according to VoteWatch data, although he was also rated one of the most influential members. Nuttall, who had a stormy six-and-a-half months as party leader, attended 52% of votes.

Farage is due to return to his full MEP salary (€8,484 pre-tax per month) in October, having being docked half of it for 10 months for alleged misspending of EU funds.

As one of the UK’s longest serving MEPs, elected in 1999, Nigel Farage would be entitled to a maximum pre-tax golden parachute of €169,680 (£149,810), if he is unable to find a job after Brexit.

However the European parliament expects MEPs to forego these payment once they have a new job. The former Ukip leader has earned up to £700,000 for his TV and radio work over the last four years - far more than his MEP salary - and hopes to continue his LBC radio show after Brexit.