He claimed that Britain's contribution to the EU will have to increase because the EU is "living beyond its means" and the European Parliament has asked for more money to spend on dealing with the migrant crisis. The UK will also be liable for additional payments to bail out eurozone countries.
However, to quote the BBC's "reality check" fact-checkers,
"The UK has a veto on the overall size of the EU budget and it's already been agreed that non-eurozone countries won't have to pay for future eurozone bailouts.
Firstly, Vote Leave says the EU has not "paid its bills" and the unpaid sum reached 24.7bn euros in 2014. It argues that when this does happen, the UK's portion of it will be £2.4 bn.
This is not how the EU works. The EU has a so-called "ceiling" on its spending. It cannot go over this upper limit.
The last time this ceiling was agreed was in 2013, for the long-term EU budget for the period from 2014 to 2020. On David Cameron's insistence, the ceiling in 2014-2020 was for the first time in the EU's history reduced in comparison to the previous period (2007-2013).
The finer detail of the EU's annual budget is agreed by qualified majority voting every year by the Council, where the finance ministers from each EU member state meet. At least 16 countries, representing 65% of the population, have to agree on the final figure, but it has to stay within the ceiling.
'Pay the bills'The European Parliament also has to agree on the annual budget and give its own proposals, which are always higher than what the member states want it to be. But what the Council agrees to always trumps against the Parliament's proposals. 'If the EU doesn't "pay the bills" - and that's the money it gives to countries for the projects such as development of poorer areas, for example - this rolls over to the next year. It's a backlog of projects the EU has committed to financing, rather than "unpaid bills".
"Rolling over to the next year" means that the EU has to adjust its spending on the future projects in order to pay for the ones to which it is already committed. The EU can never borrow in order to "pay the bills" - it leaves part of the money it has as contingency and the only other option it has is to adjust future spending, which has to be within the ceiling.
It is correct to say there will be a review of the long-term 2014-2020 EU budget some time in 2016, but the Commission has already said that there will be no changes to the ceiling. If the upper limit were to change - it would require unanimous agreement of all 28 member states.
We don't know what will happen beyond 2020. But crucially, the UK will have a veto on any decisions, including the ceiling, which affects the long-term budget plans.
Migrant crisisIt's true that the European Parliament would like to spend money on the migrant crisis. For instance, the EU and Turkey signed a deal in November 2015 to support Syrian refugees in Turkey with 3bn euros coming from reallocating money from the EU budget and another 1bn euros from the EU budget, with the rest from contributions from member states according to the size of their economies.
The UK will pay £250m - money that contributes to the UK's aid target. But unless the EU governments which gather at the European Council agree to that, this is not going to go ahead. Spending on refugees cannot raise the long-term budget ceiling.
Eurozone bailoutsThe UK will not pay for future eurozone bailouts. This has already been agreed by EU leaders.
The UK-EU deal from February, which will be implemented if the UK votes to stay in the EU, reinforces this and states that the UK would be reimbursed if the general EU budget is used for the cost of the eurozone crisis. "