VAT + inv recording in sage of EU based suppliers

UK LTD Co client uses sage - vat codes setup re EU p/l are

T23 + T 24   Zero + std  purchase of SERVICES from EU suppliers

T20               reverse charge

T7 + T 8       zero  + std purchase of SUPPLIES from EU supplier

right -

1] they receive invoices from say Google in EIRE showing EIRE Vat

2] they receive inv from SKYPE/ Luxemburg for buying skype time in uk without VAT [ having quoted uk vat reg invs now are without lux'burg vat ]

So, what vat codes should be attributed to the default supplier account

and when would you use the T20? code [ and impact on vat retrun? ]

The value of the purchases from these suppliers is very small. At what point would EC Sales forms need completion ?