Transferring money to UK from overseas as a UK citizen

I am a UK citizen planning to retire here in the next 5-10 years but still currently working overseas as Head of a British international school. As such, I want to move a substantial amount of money back to the UK and deposit it in a savings account here. Are there any limitations on how much I can move and can you confirm that, as these funds, being income generated, were subject to tax in my country of residence (El Salvador) they will not be subject to tax in the the UK (although any interest I accrued will).

Hi,
There are no tax implications for transferring savings to a UK bank account unless they generate interest or dividends. These would then potentially be subject to tax. Further guidance can be found here:
Tax on savings interest 
Tax on dividends
Thank you