It is possible to call Thailand for as little as 0.5p per minute from a UK land line using an access number or cheap calling card. The problem with doing this, you never get your Thai girlfriends phone number on your phone bill. So when you provide the embassy with your phone bills, there is no evidence to show that you talk on the phone

The answer

First find a company that allows you to make cheap calls via an access number. Then go login to your account with BT and change the access number to your Thai girlfriend’s full name

When you then print off your phone records, instead of your bill showing an access telephone number like 0844 200 25 25, it will show your Thai girlfriends name.

Phone Cheap

Phone Cheap is one company that offers calls to Thailand. Simply dial the access number next to the destination you want to call, followed by the complete international number (including country code)
Thailand Landline and mobile 0844 200 25 25 0.5p per minute

Dial Around

Dial Around offer cheap calls to Thailand via an 0844 telephone number
Dial Around is easy to use because our access numbers are available from almost any telephone in the UK

Thailand Landline 2p per minute 0844 462 34 34
Thailand mobile 0.5p per minute 0844 200 50 50

Cheapest Calls

Low-cost access numbers you can save incredible amounts on your phone bill. Without registration or pre-payment

Thailand Landline 1p per minute 0844 861 75 75
Thailand mobile 1p per minute 0844 861 75 75

Dial Abroad

Dial 0844 838 0021 for Thailand landlines and mobiles, Enter your destination number. At the prompt, enter the full international number you are calling (including the international dialling code for Thailand, which is 0066) Your connected. Enjoy cheap international calls with DialAbroad!

Talk for 2p/min to Thailand landlines and mobiles

(Check the companies web site to ensure this information and prices listed are correct and upto date)

However you are contacting your Thai partner, make sure you can get the list of calls you make as the embassy are going to need them at the time of the final visa application.