Hi Jdraw,
Thanks for offered help.

I'm trying to concatenate the comboboxes: CurrencyID and ExchangeRateID.
They are working fine when I open the form and select a currency in the CurrencyID combobox field.
However, when I open the form and select the ExchangeRateID for another value, for instance the currency rate of the next month (a purchase entered in the database on 25th of February for example will have the exchange rate code for February 2020 but when the invoice arrives 02nd of March, the cost will be booked under the March 2020 exchange rate - hence why I list the ExchangeRates and have the option to chose a month from the combobox) then it shows me all the exchange rates from all the currencies, which is not correct. Also I notice that when USD was selected in the CurrencyID combobox that it doesn't show the exchange rates in the ExchangeRateID combobox?
The ExchangeRateID combobox should only list the exchange rates based on the selected currency in the CurrencyID combobox. I was looking at a video tutorial from Richard Rost (Access Learning Zone.com ), perhaps you heard from him, on the issue and was trying to add an On Current event on the form to fix this but without any luck, I'm doing something wrong but can't figure it out...?