BK TC 14

Congratulations!
This is an optional plate from the Rems-Murr-Kreis (earlier Backnang), not from the Bördekreis!

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How do you know?
Very unusual that 2 districts can have the same code.

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Initially, prefix BK belonged to the former Baden-Württembergish district of Backnang. Because of territorial reform, that prefix was abolished in 1973.
By that time, Group A (A 1 - Z 999) and B (AA 1 - ZZ 99) plates were issued in the Backnang district. Letters B, F, G, I, O and Q were not used.

In 2007, prefix BK was introduced again in the Börde district (Saxony-Anhalt). Nobody presumed in that time of prefix liberalization to happen.
By 2013, Börde district issued remaining plates, not issued in the former Backnang district:
Group A (single letters B, F, G, I, O and Q, digits 1-999).
Group B (with letters B, F, G, I, O and Q, digits 1-99)
Group C (AA 100 - ZZ 999), with all letters.
Group D (A 1000 - Z 9999), with all letters.
Group E (AA 1000 - ZZ 9999), with all letters.

Finally, prefix BK was reintroduced as optional for the Rems-Murr district in December 2013. After this, Group A and B plates without letters B, F, G, I, O and Q started to issue there. Moreover, issues of the Group D were discontinued in the Börde district and started in the Rems-Murr district as optional.

Full information of serial issues in Germany is here.

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In the same way, prefix HZ was used for the former Branderburgish district of Herzberg, from 1991 to 1994. In 2007, this prefix was introduced again in the Harz district.
We know that Elbe-Elster district reintroduced prefix FI. Maybe, they will reintroduce prefix HZ as optional too?

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