It doesn't always cause a problem, DFS use two credit lenders,
we got our first sofa on credit no problem at all but i think i didn't pass with the first agency they used when i ordered my next lot of sofa's, probably because i already had a sofa on credit with them (we have 2 lounges).
The second agency they used asked to look at my bank statement for the last 6 months, luckily the in laws had given us a couple o grand for christmas and it was still sitting in the bank 6 months later
If you have applied for credit lots in the last 3 months then it might be a problem