Hi there,
You have the right to claim a German VAT refund regardless of how you pay for a purchase. In Germany, you can claim a VAT refund for any size of purchase (minimum amounts apply in some other countries).
However, a number of criteria must be met before you can claim the refund. You must be a legal resident of Switzerland. Not all merchants provide a VAT refund service, so make sure to ask before you make your purchase. If the store provides the necessary invoice, ask them to issue one for your purchase.
You must present the VAT refund invoice which you receive from the store along with the receipt and the purchased merchandise at the German customs office at the border and have the invoice stamped by a customs official. This must be done before you leave Germany. It cannot be done after the goods have left Germany.
With a few exceptions (alcohol, meat and dairy, for example), you can import up to 300 Swiss francs (not 300 euros!) worth of goods into Switzerland on a VAT-free basis. If you carry foreign merchandise with a combined worth in excess of 300 francs, you must declare it at a Swiss customs office when entering Switzerland.
You will be charged Swiss VAT on the value of your purchase which exceeds the 300-franc VAT-free threshold. However, you still save money because of the 300-franc allowance and because the standard Swiss VAT (7.7%) is far lower than the standard German VAT (19%).
Claiming reimbursement
Once you have obtained the clearance stamp from the German VAT office and imported the goods into Switzerland, you can have the VAT reimbursed by the German merchant from which you made the purchase. Merchants may pay out VAT in cash, or deposit it into your bank account or credit card account. They may also credit it to future purchases. The downside of reclaiming VAT this way is that it requires revisiting the German merchant from which you made the purchase. An alternative is to make use of the tax refund service offered by the SBB/CFF at many of its station offices. Using this service lets you claim your VAT refund without having to travel to Germany again, but you pay relatively high fees.
Best regards from Moneyguru
More on this topic:
Guide to changing money
Foreign currency bank account guide
Foreign currency credit card guide
Swiss bank currency exchange rate comparison
Swiss banknote rates and forex rates compared