Advice needed - approach for Stamp Duty

[verycuriousgeorge]

Hello all,

Great to meet you lovely people. Can you please share your thoughts on below?

• Background - We recently brought a property for £600k in London. Mortgage, Searches etc. sorted and now the agents are discussing Completion dates. 
• Problem - The vendor wants us to close 10 days ahead of our preferred dates. Whilst we are ok in principle, we will not have funds to cover stamp duty on the newly suggested date. Whilst we have our deposit ready and money available for solicitor fees, we will be £5k short at that date which we won't have until 10 days later.
• Question - Can we complete the transaction first and send monies for Stamp Duty 10 days later to our solicitor to file SD?

Please note we haven't yet committed to a date. Whilst there is no risk of the transaction falling through if we stick to our guns, we want to support the Vendor (a nice couple retiring to Norfolk) in any way possible. Can you share your views on the same?

Cheers,